Elen Le Foll

"I'm putting some salt in my sandwich." The use of the progressive in EFL textbook conversation

Keywords: textbook language, coursebooks, progressive aspect, textbook corpus, English as a Foreign Language (EFL), instructed second language acquisition, Spoken BNC2014, collostructional analysis, distinctive collexeme analysis, materials design

Previous studies have claimed that the progressive is frequently over-and misrepresented in English as a Foreign Language (EFL) textbooks (e.g., Römer 2005). This paper compares the representation of progressives in the dialogues of nine series of secondary school EFL textbooks (43 volumes) to the Spoken BNC2014. The frequencies, morphosyntactic and functional aspects of progressive constructions, such as contraction, negation, framing and time reference, are investigated. Collostructional analysis is used to explore the lexical associations of the progressive. A number of idiosyncratic uses of the progressive in textbook conversation are highlighted and pedagogical implications discussed. In particular, key conversational discourse-structuring phrasemes in the progressive are found to be critically underrepresented.

Background and aims

Introduction

In most non-English-speaking countries, the progressive is introduced in the first year of secondary school EFL 1 instruction. Nonetheless, the progressive vs. non-progressive alternation remains a stumbling block for many learners of English, even at higher levels of proficiency (e.g., [START_REF] Hahn | Aspect in the Chemnitz Internet Grammar[END_REF][START_REF] Rautionaho | Revisiting the ENL-ESL-EFL continuum: A multifactorial approach to grammatical aspect in spoken Englishes[END_REF][START_REF] Axelsson | The use of the progressive in Swedish and German advanced learner English -a corpus-based study[END_REF][START_REF] Wulff | Becoming a proficient academic writer: Shifting lexical preferences in the use of the progressive[END_REF]. For many EFL learners, the progressive is tricky in that it often has no direct equivalent construction in their L1 (Römer 2005: 2). To complicate matters further, it fulfils a diverse range of functions [START_REF] Mair | Progressive and Continuous Aspect[END_REF][START_REF] Binnick | Aspect and Aspectuality[END_REF]) and studies have shown that these have undergone considerable changes over the past decades (e.g., [START_REF] Mair | Why is the Progressive Becoming More Frequent in English? A Corpus-Based Investigation of Language Change in Progress[END_REF][START_REF] Smith | A Corpus-based Investigation of Recent Change in the Use of the Progressive in British English[END_REF][START_REF] Smitterberg | The progressive in 19th-century English: A process of integration[END_REF]). Whilst progressive constructions have been shown to be comparatively more frequent in spoken than in written English, corpus-informed grammars report that progressives are, in fact, rare across all varieties and registers, accounting for just three to 1 EFL = English as a Foreign Language ESL = English as a Second Language ENL = English as a Native (or first) Language L1 = First or native language L2 = Second (or more) language This is a post-peer-review, pre-copyedit version of a paper published as: Le Foll, Elen (2022). "I'm putting some salt in my sandwich.": The use of the progressive in EFL textbook conversation. In Flach, S. & M. Hilpert (Eds.) Broadening the spectrum of corpus linguistics: New approaches to variability and change. pp. 92-131 Amsterdam: John Benjamins. https://benjamins.com/catalog/scl.105.04lef.

. 2 ten percent of all verb phrases (Biber et al. 1999: 461-475;Leech, Rayson & Wilson 2001: 124-125;and Rautionaho 2014: 62-64 for a recent overview of studies on the evolution of the frequency of the progressive). At the same time, the use of the progressive in English appears to generally be on the rise in English (e.g., [START_REF] Hundt | The passival and the progressive passive: A case study of layering in the English aspect and voice systems[END_REF][START_REF] Mair | Why is the Progressive Becoming More Frequent in English? A Corpus-Based Investigation of Language Change in Progress[END_REF][START_REF] Smith | A Corpus-based Investigation of Recent Change in the Use of the Progressive in British English[END_REF][START_REF] Smith | Recent change and variation in the British English use of the progressive passive[END_REF].

The progressive aspect has repeatedly been shown to be frequently over-and misused by EFL learners, especially those acquiring English in instructional settings. For instance, learner corpus studies have concluded that L1 Finnish, Swedish and German learners generally overuse the progressive as compared to ENL speakers [START_REF] Virtanen | The progressive in NS and NNS student compositions: evidence from the International Corpus of Learner English[END_REF][START_REF] Hundt | Overuse of the progressive in ESL and learner Englishes -fact or fiction[END_REF][START_REF] Axelsson | The use of the progressive in Swedish and German advanced learner English -a corpus-based study[END_REF][START_REF] Römer | Progressives, Patterns, Pedagogy: A Corpus-Driven Approach to English Progressive Forms, Functions, Contexts, and Didactics[END_REF]. More recent, fine-grained studies have revealed how EFL learners' use of the progressive differs from ESL and ENL use in terms of frequency, range of semantic functions, choice of verb lemmas and genreawareness, among other aspects (e.g., [START_REF] Fuchs | The use of stative progressives by school-age learners of English and the importance of the variable context: Myth vs. (corpus) reality[END_REF][START_REF] Meriläinen | The progressive form and its functions in spoken learner English: Tracing the effects of an exposure-rich learning environment[END_REF]Rautionaho & Deshors 2018; for comprehensive overviews of earlier studies cf. Römer 2005: chap. 3; Rautionaho 2014: chaps. 1-2). [START_REF] Hundt | Overuse of the progressive in ESL and learner Englishes -fact or fiction[END_REF] concluded that both language contact and exo-normative influences are likely to contribute to the attested differences in progressive usage in ENL, ESL and EFL varieties. They suggest that instructed EFL learners are foremost confronted with the "grammaticality issues and semantic restrictions of the progressive, making them more likely to overuse the prototype of the construction and less likely to 'stretch' the progressive to new contexts, such as combinations with certain stative verbs or new aspectual uses" (Hundt & Vogel 2011: 160).

The present study thus explores how progressives are presented in the most important source of language input that EFL learners are exposed to in secondary school instructional settings: their textbooks. To this end, the progressives featured in EFL textbook dialogues are compared to how the progressive is used in a corpus of contemporary spoken British English (henceforth: BrE) with the aim of examining whether textbooks genuinely reflect current progressive usage in real-life conversation. In other words, this study seeks to find out whether EFL learners' well documented overand misuse of progressive constructions may, at least partially, be materials-induced.

The progressive in EFL textbooks

Compared to the many studies on English learners' use of the progressive, English language teaching materials have much more rarely been the subject of investigation. Whilst a range of lexico-grammatical features have been analysed in EFL/ESL textbooks and grammars (for an overview of "Textbook English" research from 1990 to 2009, see [START_REF] Meunier | New types of corpora for new educational challenges: Collecting, annotating and exploiting a corpus of textbook material[END_REF]; for a literature review of studies published by 2019, see Le Foll forthcoming), thus far, very few have focused on the progressive. [START_REF] Bland | The Present Progressive in Discourse: Grammar versus Usage Revisited[END_REF] and [START_REF] Belli | An Analysis of Stative Verbs Used with the Progressive Aspect in Corpus-informed Textbooks[END_REF] examined the treatment of stative verbs in the progressive in ESL/EFL pedagogical materials and concluded that it did not match authentic usage, whilst Biber & Reppen (2002: 203) reported that EFL/ESL conversation textbooks overuse the progressive in their representations of spontaneous spoken language. However, to date, only [START_REF] Römer | Progressives, Patterns, Pedagogy: A Corpus-Driven Approach to English Progressive Forms, Functions, Contexts, and Didactics[END_REF] provides a comprehensive, corpus-based analysis of the progressive in EFL textbooks. [START_REF] Römer | Progressives, Patterns, Pedagogy: A Corpus-Driven Approach to English Progressive Forms, Functions, Contexts, and Didactics[END_REF] examined the lexico-grammatical usage patterns of the progressive in a corpus of dialogues from EFL textbooks used in secondary schools in Germany. She compared those to a reference corpus of spoken BrE consisting of the spoken component . 3 of the British National Corpus (BNC 1994) and the Bank of England. Key findings include that, among the progressive verbs encountered in textbook dialogues, negated progressives and contracted forms of the auxiliary BE are underrepresented as compared to her corpus of spoken BrE, whilst question forms are overrepresented. An overuse of he and she in subject positions of progressives and an underuse of I, it, we and they are reported, as well as a distinct underuse of progressives conveying repeated actions. Although she did not directly investigate which verb lemmas are frequently featured in the progressive, [START_REF] Römer | Progressives, Patterns, Pedagogy: A Corpus-Driven Approach to English Progressive Forms, Functions, Contexts, and Didactics[END_REF] subdivided the analysis of specific morphosyntactic and functional features according to a number of individual high-frequency verbs. Thus, as compared to natural BrE conversation, present progressive forms with ASK, GO, PLAY and STAY are found to be overrepresented in textbook dialogues, but these same lemmas are seemingly underrepresented in the past progressive and present perfect progressive forms as compared to the same reference corpus.

Although by far the most comprehensive study on progressives in EFL textbooks to date, it is worth noting that [START_REF] Römer | Progressives, Patterns, Pedagogy: A Corpus-Driven Approach to English Progressive Forms, Functions, Contexts, and Didactics[END_REF] study is nevertheless based on a relatively small corpus of pedagogical dialogues stemming from just two series of textbooks (12 coursebooks) used in German secondary schools. Effect sizes or confidence intervals are not reported for the many quantitative differences observed between textbook dialogues and natural conversation. Moreover, the analyses do not enable us to tease out which parameter(s) contributed to any one reported difference in frequency of use (e.g., polarity or verb lemma, tense or time reference). Crucially, whilst the frequencies and distributions of progressive forms and functions in [START_REF] Römer | Progressives, Patterns, Pedagogy: A Corpus-Driven Approach to English Progressive Forms, Functions, Contexts, and Didactics[END_REF] textbook dialogue corpus are frequently reported separately for the two textbook series, no attempt is made to distinguish how representations of the progressive in school EFL textbooks may change as the target readers' language proficiency increases.

Aims and research questions

The present study aims to investigate how the progressive construction is portrayed in the dialogues of textbooks used at secondary school level in France, Germany and Spain, as compared to a corpus of contemporary BrE conversation (the Spoken BNC2014, see 2.1). Focusing on one register is crucial as the progressive construction has been shown to be highly susceptible to genre effects (e.g., [START_REF] Smith | A Corpus-based Investigation of Recent Change in the Use of the Progressive in British English[END_REF]Rautionaho & Deshors 2018). Conversation was chosen as lower secondary school foreign language syllabi place a strong emphasis on real-life spoken communication. The choice of conversation also allows for a comparison of the use of the progressive in EFL textbooks currently in use in secondary schools in France, Germany and Spain to that of the German textbooks featured in [START_REF] Römer | Progressives, Patterns, Pedagogy: A Corpus-Driven Approach to English Progressive Forms, Functions, Contexts, and Didactics[END_REF] corpus, which were published a decade prior. Since Römer's study did not attempt to assess the frequency of progressives, there is, to the best of the author's knowledge, currently no empirical data to back or refute the claim made by Biber & Reppen (2002: 203) that progressives are overrepresented in textbook conversation (see 1.1). Thus, in addition to variables investigated in [START_REF] Römer | Progressives, Patterns, Pedagogy: A Corpus-Driven Approach to English Progressive Forms, Functions, Contexts, and Didactics[END_REF] pertaining to the semantic functions and morphosyntactic contexts of progressives (see 2.2), the present study will also compare the overall frequency of progressive verbs in textbook and natural conversation. Moreover, all comparisons will be made at both the whole-textbook corpus level and separately for each textbook proficiency level (see 2.1).

In her concluding chapter on the pedagogical implications of her research, Römer (2005: 285) advocates for a shift towards a more lexical grammar of the progressive. This study will therefore additionally apply a collostructional approach to investigating the lexical associations of the progressive in textbook conversation. This will be achieved by comparing the results of two Distinctive Collexeme Analyses (DCAs) of the lemmas associated with both progressive and non-progressive constructions in textbook dialogues and real-life conversation. Although there have been successful multifactorial approaches to the study of progressives in different genres and ENL, ESL and EFL varieties (e.g., [START_REF] Rooy | The extension of the progressive aspect in Black South African English[END_REF][START_REF] Fuchs | An apparent time study of the progressive in Nigerian English[END_REF][START_REF] Deshors | Zooming in on verbs in the progressive: A collostructional and correspondence analysis approach[END_REF]Rautionaho & Deshors 2018;[START_REF] Rautionaho | Revisiting the ENL-ESL-EFL continuum: A multifactorial approach to grammatical aspect in spoken Englishes[END_REF], so far, such models have not included verb lemma as an independent variable.2 Excluding the variable lemma from such an analysis, however, is potentially problematic both from a theoretical, usage-based approach, and a pedagogical perspective. Indeed, the aspect hypothesis, which is in turn motivated by the distributional bias hypothesis, postulates that:

First and second language learners will initially be influenced by the inherent semantic aspect of verbs or predicates in the acquisition of tense and aspect markers associated with or affixed to these verbs (Andersen & Shirai 1994: 133).

In line with the predictions of the aspect hypothesis, [START_REF] Bardovi-Harlig | After process, then what? A longitudinal investigation of the progressive prototype in L2 English[END_REF] advances that EFL learners first acquire the progressive aspect in the context of activity verbs and accomplishment. They later on extend the construction to repetitive (iterative and habitual) actions, before beginning to use it in futurate and, finally, stative functions. Supporting the aspect hypothesis, Rautionaho & Deshors (2018) report that, in their final regression model of progressive use by ENL, ESL and EFL speakers, only the semantic domain variable does not contribute to any higher-level interactions. They thus conclude that "regardless of varieties, written genres, tense, Aktionsart [accomplishment, achievement, process, or stative], voice, etc., the semantics of a given lexical verb systematically influences writers constructional choices" (Rautionaho & Deshors 2018: 238). Since lemma and semantic category are usually highly correlated, we might speculate that, if it were feasible to include them in such a model, individual verb lemmas may play an even more important role than semantic domain in mapping the use of the progressive. In the context of this pedagogically-motivated study, it therefore seems imperative to also consider which specific verb lemmas are more strongly associated to the progressive as opposed to the non-progressive in EFL textbooks and naturalistic conversation.

Against this background, the following five research questions were formulated:

1. Is the progressive overrepresented in textbook conversation as compared to a corpus of naturally-occurring BrE conversation? 2. What are the morphosyntactic contexts in which EFL learners encounter progressives in textbook dialogues? Are these contexts representative of those found in conversational BrE recorded in natural settings? 3. Which functions do progressives in textbook conversation typically fulfil? Are these representative of the most common functions observed in the Spoken BNC2014? 4. Have the progressives featured in textbook dialogues become more representative of those typical of BrE conversation than was the case at the time of [START_REF] Römer | Progressives, Patterns, Pedagogy: A Corpus-Driven Approach to English Progressive Forms, Functions, Contexts, and Didactics[END_REF] study? 5. Which lexical verbs and semantic domains are significantly associated with or repelled by the progressive in textbook conversation? How does this compare to the Spoken BNC2014?

In analysing and evaluating the results, the discussion section will seek to find out whether any of the differences noted in the use of progressives in textbook vs. naturalistic BrE conversation may be pedagogically well-founded and/or whether any of the observed discrepancies might deprive EFL learners of valuable exposure to particularly frequent and salient forms and functions of the progressive.

Methodology

This section first presents the corpus data analysed in the context of this study (2.1), before turning to how the corpora were queried, the query results automatically preprocessed, and subsequently manually annotated for a number of morphosyntactic and functional variables (2.2). Sections 2.3 and 2.4 outline the statistical methods used to compare frequencies across the two corpora. The final section (2.5) briefly explains the procedure followed to conduct the collostructional analysis of the lexical verbs attracted to or repelled by the progressive in textbook and natural conversation.

Corpus data

The textbook data explored in this paper is a subcorpus of the Textbook English Corpus (TEC) which was compiled as part of a larger research project on 'Textbook English' (Le Foll to appear; forthcoming). The TEC consists of 43 EFL textbooks used in secondary schools in France, Germany and Spain and totals just over two million words. It consists of nine best-selling textbook series from eight major publishers. Each series corresponds to the first four or five years of English instruction at secondary school level (see Appendix: Table 14 for details). The 43 textbooks were converted to XML format and manually annotated for six textbook registers (conversation, informative texts, personal communication, instructional, song & rhyme, and contextless words/sentences, e.g., exercises) and automatically lemmatised tagged for part-of-speech using the Sketch Engine's (Kilgarriff et al. 2014) default options (English TreeTagger v. 3.3).

This paper explores the conversation subcorpus (henceforth, Textbook Conversation Corpus, TCC) of the TEC. The TCC brings together all the printed dialogues, speech bubbles, as well as the scripts and transcripts of the video and audio conversation material from the 43 textbook volumes of the TEC. With some 420,000 words, the TCC is relatively large for such a specialised corpus. By way of comparison, [START_REF] Römer | Progressives, Patterns, Pedagogy: A Corpus-Driven Approach to English Progressive Forms, Functions, Contexts, and Didactics[END_REF][START_REF] Römer | Looking at looking: Functions and contexts of progressives in spoken English and 'school' English[END_REF] textbook dialogue corpus (GEFL TC) totalled 108,000 words.

The TCC is compared to the Spoken BNC2014, an 11.4-million-word corpus of orthographically transcribed conversations among L1 speakers in the UK [START_REF] Love | The Spoken BNC2014[END_REF]) in a custom version uploaded onto Sketch Engine (Le Foll forthcoming). Basing comparisons on a reference corpus of BrE may be considered a limitation, especially since a number of studies have reported significant differences in progressive usage between various ENL varieties (cf. [START_REF] Hundt | Overuse of the progressive in ESL and learner Englishes -fact or fiction[END_REF][START_REF] Deshors | Zooming in on verbs in the progressive: A collostructional and correspondence analysis approach[END_REF][START_REF] Rautionaho | Revisiting the ENL-ESL-EFL continuum: A multifactorial approach to grammatical aspect in spoken Englishes[END_REF]). However, although no longer explicitly mentioned in the national curricula, school EFL instruction in Europe remains largely oriented towards (Southern) BrE norms (Preisler 2002: 239;cf. Bieswanger 2012;[START_REF] Gilquin | American and/or British influence on L2 Englishes -Does context tip the scale(s)?[END_REF][START_REF] Syrbe | An evaluation of the global orientation of English textbooks in Germany[END_REF] and, in practice, the textbooks featured in the TEC overwhelmingly focus on the U.K., both in terms of language use and cultural contextualisation.

. 6

Data extraction and annotation

The aim was to retrieve all instances of progressives from the TCC and to subsequently extract, at random, a comparable number of progressives from the Spoken BNC2014 for comparison (see 2.5). Sketch Engine's advanced search option and the following CQL (Corpus Query Language) query were used to this effect:

(1) [tag="VB.*"][tag!= "SENT"]{0,3}[tag="V.G" & word!="gonna"]

The query allows for a maximum of three intervening tokens (except end-of-sentence punctuation [SENT]) between the auxiliary BE [VB.*] and the V-ing form [V.G], e.g., a negation and/or other intervening adverbs, or a nominal phrase as a subject in question forms. The form gonna, which is tagged as a V-ing form by the Sketch Engine, was explicitly excluded from the query because it is mostly associated with going to + Vinfinitive constructions expressing future actions and events, which were excluded from the present investigation.

Next, false positives, i.e. non-progressives that were unintentionally retrieved by the corpus query (1), were filtered out. This included nouns and adjectives ending in -ing and erroneously tagged as present participles, BE going to + Vinfinitive constructions, non-finite verb phrases (e.g., she continued reading) and elided constructions (see [START_REF] Smitterberg | The progressive in 19th-century English: A process of integration[END_REF][START_REF] Rautionaho | Variation in the progressive a corpus-based study into world Englishes[END_REF] for similar procedures).

Finally, the remaining concordance lines were annotated for a range of morphosyntactic and functional features chosen on the basis of previous corpus linguistics studies on the progressive aspect (in particular, [START_REF] Römer | Progressives, Patterns, Pedagogy: A Corpus-Driven Approach to English Progressive Forms, Functions, Contexts, and Didactics[END_REF][START_REF] Rautionaho | Variation in the progressive a corpus-based study into world Englishes[END_REF][START_REF] Deshors | Zooming in on verbs in the progressive: A collostructional and correspondence analysis approach[END_REF]. To this end, regular expressions and the lemmatising function of the R package {textstem} [START_REF] Rinker | textstem: Tools for stemming and lemmatizing text in R. Buffalo[END_REF] were used to annotate easily operationalisable features: verb lemma, contraction, negation and tense form. Then, question form, voice, time reference and the functional features that emerged from Römer's corpus-driven work on the progressive in spoken BrE were manually coded (Römer 2006: Appendix). Over the course of the first annotation cycle, a few minor changes to Römer's categorisation were deemed necessary: the functional category 'habits' was merged with the category 'repeatedness' due to large overlaps, and the categories 'emphasis/attitude' and 'shock/disbelief' were merged into one broader category due to disambiguation issues (see Table 1 for the final annotation scheme).

Half the concordance lines were annotated by the present author and the other half by a research assistant. 3 The interrater agreement on two double-blind annotated random samples of 100 progressives from each corpus across nine (partially) manually annotated variables was satisfactorily high (96.22%). Only the 'continuous/non-continuous' variable proved particularly sensitive to subjective interpretation. Following discussions, it was agreed to follow Römer's (2005: 87-88) criteria ("procedural", "extension over a certain time span" vs. "short-term actions", "punctiform") as closely as possible. The label 'unclear' was applied for cases which lacked the necessary context to make a reliable decision on any variable.

Calculating the frequency of progressives

To calculate the relative frequency of progressives, the two corpora were additionally tokenised, dependency parsed and POS-tagged using spaCy [START_REF] Honnibal | spaCy 2: Natural language understanding with bloom embeddings. Convolutional neural networks and incremental parsing[END_REF].

The POS and syntactic dependency parsing information was used to identify all finite verb phrases (FVP) and their head verb lemma using a custom R script (Le Foll forthcoming). This allowed for a normalisation basis to calculate the relative frequency of progressives that excludes non-finite verbs. This was necessary because these are not included in the progressive count either (see 2.2). To compare the relative frequencies of the progressive, Smitterberg (2005: 45-48) also advocates the exclusion of certain constructions in which the progressive never occurs from the normalisation baseline, i.e., imperative and BE going to + Vinfinitive constructions. Automatically excluding imperatives proved computationally difficult, but since BE going to + Vinfinitive constructions were captured by the CQL extraction process, and manually tagged for exclusion from the progressive count, these could easily be subtracted from the total verb count. In the present study, the relative frequency of the progressive was thus measured as:

. 8

(2) Rel. freq.PROG = NPROG / (NFINITE_VERB_PHRASES -NPROG -NGOING_TO) × 10,000

Comparing frequencies

All χ 2 tests conducted for this chapter were performed using the default settings of the chisq.test() function in base R. As such, Yates' continuity correction was applied for all two-by-two tables. A prerequisite for χ 2 tests is that the observations be independent.

Although arguably the most widely used significance test in quantitative (corpus) linguistics, it can be convincingly argued that this condition is not met since many of the progressives under study will come from the same textbook (volume or series) and have therefore been written by the same group of authors. Some will even come from the same text (but cf. Le Foll 2020 on the difficulty of defining text units in school textbooks).

Since the majority of the speakers of the Spoken BNC2014 can be expected to have produced more than one progressive, the same issue occurs with the natural conversation data. However, this is much less likely to yield undue influence on the results because only a small subset of progressives was randomly sampled from the full corpus. For the purposes of this study, every FVP is considered an independent data point. Nonetheless, all quantitative comparisons were additionally tested for potential differences across the nine textbook series, five textbook proficiency levels, and three countries of use (France, Germany or Spain). For reasons of space, the results of these comparisons are only reported when significant patterns emerged.

The results of the null-hypothesis significance tests are complemented with effect size measures. In the case of two-by-two comparisons, φ coefficients are used. For larger contingency tables, Cramér's V is reported. Both were calculated using the default parameters of the assocstats() function from the {vcd} package [START_REF] Meyer | vcd: Visualizing categorical data[END_REF]. The {vcd} package was also used to produce the association plots used to visualise the results.

Collostructional analysis

Collostructional methods (cf. [START_REF] Stefanowitsch | Collostructions: Investigating the interaction of words and constructions[END_REF] aim to measure the strength of the relationship between a construction (e.g., the progressive) and a collexeme (e.g., the verb PUT). The advantage of such a bidirectional measure is that the resulting metric, collostructional strength (hereafter CollStr), assesses whether the co-occurrence frequency of a collexeme in a construction is significantly different to what we would expect under the assumption of no association given the construction's and collexeme's overall frequencies within a corpus.

In this paper, two progressive vs. non-progressive Distinctive Collexeme Analyses (henceforth DCA) [START_REF] Gries | Extending collostructional analysis: A corpus-based perspective on "alternations[END_REF] were conducted using the {coll.analysis} package for R (Gries 2019a): one DCA for the TCC and one for a sample of the Spoken BNC2014. The results are used to compare the extent to which individual lexical verbs are attracted to either the progressive or non-progressive constructions in textbook and naturalistic BrE conversation.

For both datasets, the total number of FVP per verb lemma were automatically counted using the using POS tags and dependency information from the Spacy model (see 2.3). The counts of the progressive FVPs, on the other hand, were the result of the manual post-processing of the CQL query hits (see 2.2), which, for the TCC, narrowed down the 3,380 query results to 2,423 annotated progressives. This number corresponds to the total number of FVP in the progressive listed in the example contingency table for the lemma SAY in the TCC printed in Table 2. Given the high percentage of false positives retrieved by the CQL query (28% in the TCC), manual filtering was inevitable, which is why, unlike the progressive vs. nonprogressive DCA of the TCC data, the DCA of the natural conversation data could not be conducted on the full Spoken BNC2014 corpus. Instead, a random sample of 57,007 FVPs, corresponding to the total number of FVPs in the TCC, was extracted from the Spoken BNC2014. Within this sample of FVPs, the CQL query returned 4,641 hits, which were manually filtered for progressives (see 2.2). This process resulted in a total of 3,444 progressives (see Table 3), of which the first 2,423 were annotated in detail following the procedure outlined in 2.2.

Results

Frequency of progressives

The frequency of progressives in the TCC was found to be 395.5 progressives per 10,000 finite verb phrases (FVPs). By contrast, there were 558.0 per 10,000 FVPs in the Spoken BNC2014 sample. The results therefore make clear that, even when accounting for the lower number of verbs and FVPs in the TCC, the frequency of progressives is considerably lower in the TCC than in the Spoken BNC2014 (χ 2 (1) = 191.81, p < 0.001, φ = 0.038). This finding contradicts the claim made by Biber & Reppen (2002: 203) that the progressive aspect is overrepresented in textbook representations of natural conversation.

Morphosyntactic features

The following sections compares the morphosyntactic features of progressive constructions in textbook and natural conversation. The following analyses are based on all 2,423 progressives retrieved and annotated from the TCC, as compared to a random sample of 2,423 annotated progressive concordance lines from the Spoken BNC2014.

Tense, aspect and modality

This section begins with an exploration of the results of the TCC vs. Spoken BNC2014 comparisons across all textbook levels as in [START_REF] Römer | Progressives, Patterns, Pedagogy: A Corpus-Driven Approach to English Progressive Forms, Functions, Contexts, and Didactics[END_REF] study. Römer (2005: 244) reported that textbook dialogues overuse the present progressive as compared to natural BrE conversation. At first sight, the distributions of forms of the progressive (see Table 4) appear to back this finding for the more recent school EFL textbooks featured in the TCC, too. Additionally, Römer (2005: 271) observed an underrepresentation of perfect progressives with a number of high-frequency verbs (e.g., ASK, GO, PLAY and STAY). The results presented in Table 4, however, suggest that perfect progressives are, if anything, overrepresented in textbook dialogues as compared to the Spoken BNC2014. The final 'modal' category agglomerates all progressive forms with CAN, COULD, HAVE TO, MAY, MUST, SHOULD, WILL and WOULD. Though still very marginal, the proportion of modal progressives relative to other progressive forms is almost twice as high in the Spoken BNC2014 sample as in the TCC (see Table 4). In the Spoken BNC2014, WILL and WOULD clearly dominate (3)-( 4), whereas the textbooks feature the full range of modal progressive constructions, e.g., (5), thus with very low frequencies of occurrence for each modal type per textbook series.

(3) Nunnington Hall will be reopening soon cos it will it? closes over winter <BNC2014: SQ4F>4

(4) yeah well you've got so many things on your plate anyone would be feeling the same <BNC2014: SRNT>

(5) Mum: I hope you're not getting involved with that brother of hers. Rob isn't the sort of boy you should be mixing with. <TCC: Green Line New 3> Fig. 1 is an association plot of the data summarised in Table 4. For each cell in Table 4, the height of the bars corresponds to the difference between the observed and expected frequencies divided by the squared root of the expected value, also known as the Pearson residual. The width of the bars is proportional to the squared root of the expected value, whilst the colour indicates the sign of the residual and its relative importance: the more intensive, the greater the deviation from the expected value. In other words, Fig. 1 shows that the most striking difference in form distribution iscontrary to what the values reported in Table 4 may suggestobserved in the past progressive, rather than in the present progressive. Whilst all categories make significant contributions to the χ 2 statistic at the significance level of 0.01, the past progressive is the category that makes the greatest contribution to this difference in the distribution of progressive forms across the two corpora. Given that more complex forms such as past, perfect and modal progressives are unlikely to be introduced in the first few years of EFL instruction, the distribution of progressive forms was also subdivided by textbook level (see Table 5 and Fig. 2). As expected, the beginner textbooks almost exclusively feature present progressive forms, whilst perfect and modal progressives are not introduced until the third year of EFL instruction. It is also worth noting that, once they have been introduced, perfect progressives are in fact overrepresented in textbook conversation. Modal progressives, on the other hand, are introduced more gradually. Fig. 2 shows that the present progressive is not overrepresented in more advanced textbooks. Crucially, however, it makes clear that past progressives are underrepresented across all textbook levels.

Contractions

In spoken English, verb contractions are very frequent and, indeed, out of the 2,423 progressive concordance lines extracted at random from the Spoken BNC2014, over half (53%) feature a contracted form of the auxiliary BE. Taken as a whole, the proportion of contracted forms in the TCC is only marginally lower (46%) than that of the reference corpus (χ 2 (1) = 20.87, p < 0.001, φ = 0.07). However, a more fine-grained view of the proportions per textbook series reveals a rather different picture (see Table 6).

. 13 The two lowest proportions of contracted forms come from French textbooks: Join the Team (Nathan) and Piece of Cake (Le Livre Scolaire). By contrast, the dialogues of the German series Access (Cornelsen) and the Spanish edition of English in Mind (Cambridge University Press) display ratios of contracted to full forms of the progressive that are very similar to those observed in the Spoken BNC2014. It is also notable that the frequencies of contracted progressives in the dialogues of the series Green Line (Klett) are just as low in its 2014-2018 edition (Green Line New) as in the older version dating from 2006-2009 (Green Line), though this still represents a notable improvement on the percentage of contracted progressives reported in Römer (2005: 245), namely 32.90%.

Negation

Römer (2005: 250-251) reported a considerable underruse of negated progressives in textbook dialogues with shares of negated progressives almost twice as high as in her reference spoken BrE data. As a possible explanation, she advanced that textbook conversation may be "closer to writing than to actual speech" (Römer 2005: 250). In the present study, the proportion of negated progressives observed in the TCC is only very marginally lower than in the Spoken BNC2014 sample (see Table 7). Interestingly, this difference is not due to higher proportions of negated progressives in more recent textbooks publications, but rather because the Spoken BNC2014 has a lower share of negated progressives (6.5%) than Römer's reference corpora (7.98% and 8.59%). However, qualitative differences in the functional and semantic contextual use of negated progressives were observed. Thus, in textbook conversation, negated progressives are typically found where an action is not taking place (6) or a state is negated (7). By contrast, naturally occurring spontaneous conversation features many misunderstandings which call for clarifications, and these frequently rely on negated verbs in the progressive ( 8)-( 9).

(8) I am not talking about finding a job <BNC2014: S2FQ>

(9) hold on we're not using that one <BNC2014: S632>

Questions

Römer (2005: 252) observed almost twice as many progressives in interrogative contexts in textbook dialogues as in naturally occurring speech. This trend is confirmed in the present analysis, albeit with a very small effect size (see Table 8).

Voice

Smith (2005: chap. 6) reports that progressive passives have seen a dramatic increase in contemporary BrE but demonstrates with cross-register comparisons that conversation still has the lowest relative frequency. The present results confirm low frequencies of passive progressives for both the TCC and the Spoken BNC2014 sample. No significant difference between the two corpora was observed (see Table 9). However, qualitative differences in the degree of colloquialism can be observed. Out of 23 passive progressives, the Spoken BNC2014 sample features six GET-passives ( 15) and one HAVE-passive in the progressive ( 16).

(15) how much am I getting paid? <BNC2014: SA7J> ( 16) cos I know some women they're find it a bit difficult mm to cope with the fact that they're having their lady bits taken away <BNC2014: S28F>

These alternative, more colloquial, passive forms are entirely absent from the TCC. Instead, the BE-passives featured are more typical of written genres than spontaneous conversation ( 17)-( 18).

(17) Countries that still use leaded petrol are being urged to stop using it […]. <TCC: Solutions Intermediate Plus> [START_REF] Römer | Looking at looking: Functions and contexts of progressives in spoken English and 'school' English[END_REF] Today in South Africa about one third of our water is being wasted because of old pipes and insufficient infrastructure. <TCC: New Mission 2 e >

Functions of the progressive

Time reference

As attested by the relatively high proportion of progressives assigned the label 'unclear' in Table 10, time reference was undoubtedly the most difficult aspect to code. Both Table 10 and Fig. 3 reveal considerable differences in the distributions of the time period referred to by progressive constructions in the TCC and the Spoken BNC2014 sample. The largest numerical differences are found in the categories 'past' and 'present' time reference, but considering the distribution of forms reported in 3.2.1, this was to be expected. The category 'past/present' time reference refers to events and situations which started in the past and are ongoing ( 19), a category that is overrepresented in textbook conversation. This finding also corresponds to the overrepresentation of present perfect progressive forms in the TCC (see 3.2.1).

(19) Come on! We've been waiting for fifteen minutes already! <TCC: Green Line 4> In addition, cross-tabulations of tense forms and time reference also revealed that BrE native speakers are more likely to resort to modal progressive constructions (foremost WILL + BE + V-ing) to refer to (possible) future events, as in (3), than the (hypothetical) speakers featured in the textbook dialogues.

(Non-)Continuousness

Many EFL grammars, and indeed the three Spanish textbook series from the TCC (see Appendix 1), refer to the progressive construction as "the continuous". This term may mislead learners to believe that progressive constructions always refer to continuous activities, whereas more than a fifth of progressives in the Spoken BNC2014 sample actually refer to 'non-continuous' actions ( 22). In the TCC, progressives are significantly less frequently used to refer to 'non-continuous' actions.

(

Repeated actions and states

As shown in Table 11, progressives that express repeated actions or states are less frequent in the TCC than in the Spoken BNC2014 ( 28)-( 29).

(28) oh they've taken the one that you put er compostables in and garden rubbish so that means people are putting them in the black bins < BNC2014: SRWD> (29) she was trying to multitask everything that was going on in her life mm she's she was like getting chest pains and stuff from it <BNC2014: ST47> Although the effect size reported in Table 11 is small, as previously pointed out by Römer (2005: 284), if learners are not adequately exposed to this core function of the progressive, this could potentially lead to genuine misunderstandings. For instance, EFL learners may not recognise the repeated nature of the actions reported on in extracts ( 28)-( 29) from the Spoken BNC2014.

Additional functions of the progressives

Table 12 summarises the number of progressives coded with additional functions following an adaptation of [START_REF] Römer | Progressives, Patterns, Pedagogy: A Corpus-Driven Approach to English Progressive Forms, Functions, Contexts, and Didactics[END_REF][START_REF] Römer | Looking at looking: Functions and contexts of progressives in spoken English and 'school' English[END_REF] functional categories (see 2.2). The null hypothesis that there is no association between the prevalence of any one of these additional functions and the two datasets under study can be rejected for the categories 'framing' and 'gradual change/development'. The considerable overrepresentation of progressives in a framing context in textbook dialogues undoubtedly stems from the fact that the framing function is very much central to descriptions of the progressive in the respective grammar sections. It is given particular emphasis when the past progressive is introduced, as a way of contrasting the past simple and the past progressive. This framing function of the past progressive is modelled in many textbook dialogues, e.g., ( 30), ( 31) and ( 52), but is, in fact, comparatively rare in conversational BrE (see Table 12). ( 30) Sorry I missed your call yesterday. I was having my dance class when you rang. <TCC: Hi There 5 e > ( 31) Well, I was jogging in the park and then I found her wandering around, all on her own. <TCC: Green Line New 2>

Lexis

The analyses presented thus far have focused on various morphosyntactic and functional aspects of progressive constructions. In the following, the lexis of progressive constructions is examined through the lens of the progressive vs. non-progressive alternation. To this end, the results of two Distinctive Collexeme Analyses (DCAs) are compared in Table 13: negative CollStr values (G 2 ) represent repulsion of the progressive, in other words, attraction to non-progressive constructions. Note that, as explained in 2.5, the results reported on in this section are based on a slightly larger sample of the Spoken BNC2014 (57,007 FVPs, of which 3,444 progressives) than for previous analyses. In both halves of Table 13, the collexemes that display a much stronger attraction to the progressive than the non-progressive belong to the broad semantic domain of activity verbs (e.g., TALK, DO, GO, WORK, PLAY, STUDY). This corresponds to a prototypical use of the progressive, often the very first one to be introduced in EFL textbooks ( 32)-( 33). [START_REF] Mair | Progressive and Continuous Aspect[END_REF] Present progressive: To say that somebody is currently in the process of doing something. E.g. She is watching TV. <Green Line 1> [START_REF] Rooy | The extension of the progressive aspect in Black South African English[END_REF] Present progressive: To talk about things that are happening now. E.g. I'm reading on the roof. <English in Mind Starter>

Over the course of the manual annotation process, it was noted that some 80 occurrences of the present progressive in the TCC were part of picture or film descriptions. This is because secondary school textbooks rely heavily on picture description tasks as a means of enabling learners to practise using the progressive and textbooks include model dialogues of the intended outcome of such group picture/film description tasks (34). This task effect contributes to the high positive CollStr values of verbs such as WEAR, RAIN, SMILE, STAND and WALK in the textbook data (see The most striking differences between the results of the two progressive vs. nonprogressive DCAs are visualised in Fig. 4: each point represents one verb lemma. All verb lemmas are included except BE, which returned very negative CollStr values in both DCAs (see Table 13). It was removed before the CollStr values were standardised (to z-scores) to avoid this one verb exerting undue influence on the results. The scatterplot makes clear that the CollStr values that emerged from the two DCAs are very highly correlated (Pearson's r(447) = 0.98, p < 0.001). We may therefore conclude that there are only few verbs that are considerably more or less attracted to the progressive in the TCC than in the Spoken BNC2014 sample. The labelled points on Fig. 4, however, correspond to the twenty lemmas with the greatest absolute differences in standardised G 2 values (> |1.25|).

The rest of the analysis will focus on these verbs. We will begin by examining the bottom left quadrant with negative standardised G 2 values. These points correspond to verb lemmas repelled by the progressive construction in both corpora. The labelled points in this quadrant are all found to the left of the regression line. These are stative verbs and verbs of involuntary perception that textbooks frequently list as "exception" or "state verbs" that cannot be used in the progressive (cf.

Niemeier 2017: 109), e.g., LOVE, LET (in the sense of ALLOW), SEE (as a verb of involuntary sensory perception) and WANT. However, the present results show that, in natural BrE conversation, stative verbs, in particular, do not occur in the progressive quite as rarely as EFL grammars would suggest (36)-( 39).

(36) so I ended up going and babysitting well the daughter's probably eleven right something like that erm so was kind of letting her be in charge you know <BNC2014: S8BQ>

(37) why don't you let me buy a b Park Lane? no I'm not letting you buy Park Lane <BNC2014: SXK5>

(38) and yeah she was like oh she she she was loving she was loving the fact she was being recorded though like <BNC2014: S6BS>

(39) yeah are you wanting that tape back? no are you sure? yeah you leave it here <BNC2014: S2KP>

Among the labelled verb lemmas in the bottom left quadrant of Fig. 4, THINK constitutes a special case. It is repelled by the progressive construction in the textbook conversation corpus, but shows no significant association to either the progressive or the nonprogressive construction in the Spoken BNC2014 sample. A qualitative exploration of the corresponding concordance lines shows that, in EFL textbooks, THINK is primarily used in non-progressive constructions to give opinions ( 40)-( 41). In addition, textbook dialogues feature THINK to express doubt (42) or hedge statements (43). There is no doubt that these functions are also very common in naturally occurring speech.

The qualitative concordance analysis revealed that the difference observed in Fig. 4 is, in fact, foremost driven by just one progressive discourse-structuring phraseme: I'm/was thinking (44)-( 45), which is almost ten times more frequent in the Spoken BNC2014 (1,899.6 occurrences per 10,000 words in the Spoken BNC2014 [N= 2,444]) than in the TCC (196.7 per 10,000 words [N = 10]).5

(44) Stockholm Copenhagen Copenhagen yeah I haven't really been to Scandinavia that's really funny cos I was thinking that as well I was thinking if grandad was here yeah <BNC2014: S6JP>

In addition to THINK, the remaining verb lemmas to the left of the regression line on Fig. 4, SAY, TALK and, in many cases, also TRY, are also frequently used in natural conversation within relatively fixed discourse-structuring phrasemes that feature present or past progressive forms (45)-( 47).

(45) absolutely so now I was thinking about it just as you were talking and I was talking I was thinking because dad doesn't really want me to have my own life <BNC2014: S6HP> (46) cos she was saying um oh I just want to be on the boat <BNC2014: SBYQ> (47) yeah like what I'm trying to say really is that if had plenty of time <BNC2014: SBG4>

Conversely, Fig. 4 shows that another verb belonging to the semantic domain of communication, KID, is more strongly associated with the progressive construction in the TCC than in the Spoken BNC2014 sample (unlike JOKE, which ranks high on both collexeme lists in Table 13). Whilst textbook authors clearly favour the interrogative phraseme are you kidding (me)? and the explosive you're kidding!, the Spoken BNC2014 also features the non-progressive phrase I kid you not. Before arguing for the inclusion of this particular phraseme in textbook dialogues, however, it should be noted that it is very unevenly dispersed across the Spoken BNC2014: 19 out of the 29 occurrences were uttered by just one speaker (S0439, a 23 year old female L1 speaker).

In a similar vein, the lemma COME is more strongly attracted to the progressive in naturalistic BrE conversation than in the TCC as a result of two phrasemes frequently featured in textbook dialogues: come on! (48) and the phrasebook classic I come from [country/town] (49). It also worth noting that the most frequent one-to-the-right collocates of COME in the TCC are on, to, from and here. By contrast, in the Spoken BNC2014, back, out, in, to and up are most frequently paired with COME and these phrasal verbs are more likely to occur in the progressive, as in ( 50)-( 51).

( To the right of the regression line in Fig. 4 we find verbs that are more strongly associated with the progressive in the TCC than in the Spoken BNC2014. The case of KID has already been discussed. As noted in the discussion of the results in Table 13, DO, PLAY and STUDY are instantiations of the kinds of activity verbs that are frequently used by textbook authors as model, prototypical verbs for the progressive construction. Similarly, WEAR, STAND and SMILE have been shown to be frequently featured in textbook dialogues modelling picture description tasks designed to provide learners with the opportunity to practise using the progressive.

The remaining lemma on this side of the scatterplot, WAIT, is also associated with how the progressive is traditionally taught in EFL textbooks and grammars: textbook authors make frequent use of WAIT as a means of featuring present and past perfect progressives in dialogues (19). It is also a useful verb to demonstrate the progressive's framing function (see 3.3.4) (52).

(52) A full-blown fight broke out between the two groups and someone went to get a teacher. While we were waiting out outside the head teacher's office, we got talking and he said something that made me laugh. <TCC: Solutions Intermediate> Finally, the appearance of the lemma RECORD as a verb noticeably associated with the progressive in the Spoken BNC2014 both in Table 13 and on Fig. 4 is clearly an artefact of the data collection process. The spoken component of the new British National Corpus (BNC2014) was created by encouraging members of the public to record their conversations on their own smartphones (Love et al. 2017: 329). This unusual set-up prompted regular remarks by the interlocutors of the conversations featuring RECORD in the progressive (53). Hence, more than anything else, the presence of RECORD in these results serves as a reminder of the inherent difficulty of obtaining genuinely "authentic" or "naturally occurring" speech data.

(53) oh you're still oh er you're recording? oh you're not recording this? yeah yeah it's perfect perfect talk <BNC2014: SAUR>

Discussion and limitations

The analyses of the morphosyntactic, functional and lexical aspects of progressives in the TCC and the Spoken BNC2014 presented in the preceding sections have pointed to many idiosyncrasies in the use of the progressive in textbook dialogues as compared to naturalistic BrE conversation. This section begins by revisiting the five research questions (RQs) enumerated in 1.3, before turning to the study's limitations. Section 5 concludes with some remarks on potential pedagogical implications and recommendations for textbook authors, editors and publishers.

Starting with RQ1, contrary to the claim made by Biber & Reppen (2002: 203), the results indicate that progressives are not overrepresented in EFL textbook conversation; if anything, they are, in fact, underrepresented compared to native BrE conversations (see 3.1). As for RQ2, the results highlight both similarities and a few notable divergences in the morphosyntactic contexts of progressives in textbook dialogues as compared to BrE conversation. Past progressive forms were found to be significantly underrepresented in the TCC, even after making allowances for the late introduction of this tense form in school textbook series (see 3.2.1). The TCC also marginally underrepresents contracted forms of the progressive. However, the ratio of contracted to non-contracted progressives varies markedly across different textbook series, with two French series faring particularly poorly (see 3.2.2). Negated progressives were also seen to be underrepresented (see 3.2.3).

In contrast, progressives in interrogative contexts are significantly overrepresented (see 3.2.4). In addition, the negated and question-form progressives featured in textbook dialogues differ substantially from those found in naturally occurring speech, both in terms of syntax and pragmatic use. Though the proportions of active and passive progressives are not significantly different, the Spoken BNC2014 features more colloquial GET-and HAVE-passives, whereas the TCC exclusively features being + Ved passive constructions (see 3.2.5).

RQ3 examined the functions of progressives. When taking the effect of the gradual increase in complexity across textbook levels into account, tense, aspect, modality and time references are distributed fairly similarly across the TCC and the Spoken BNC2014. Nevertheless, the results revealed that progressives referring to generally valid statements and hypothetical situations are markedly underrepresented in the TCC (see 3.3.1). Moreover, futurate progressives are proportionally more frequently expressed with a present progressive, whereas modal constructions, foremost WILL + be + Ving, are underrepresented compared to the Spoken BNC2014 (see 3.2.1). Progressive constructions referring to repeated actions and to non-continuous actions are also underrepresented (see 3.3.2-3.3.4). Progressives used in framing contexts were shown to be twice as frequent in the TCC as in the Spoken BNC2014, where they were found to be remarkably rare (see 3.3.4).

In answer to RQ4, whilst some of the trends observed by [START_REF] Römer | Progressives, Patterns, Pedagogy: A Corpus-Driven Approach to English Progressive Forms, Functions, Contexts, and Didactics[END_REF] were confirmed, others were not. For instance, whereas Römer (2005: 244) reported that textbook conversation overused the present progressive, it was made clear that this trend is only true of beginner textbooks (see 3.2.1). In fact, there may be good pedagogical reasoning behind this choice since present progressives are by far the most frequent variant in spoken English. Also in contradiction with Römer's findings (2005: 271), perfect progressives were not found to be underrepresented once introduced. In alignment with previous research (Römer 2005: 244-266), past progressives, however, are considerably underrepresented across all textbook levels. Furthermore, the more recent versions of the German textbook series Green Line (published 2006-2009 and 2014-2018) still appear to underrepresent contracted progressives (see 3.2.2), though noticeably less so than in the older version examined by Römer (pub. 1995[START_REF] Conrad | Will Corpus Linguistics Revolutionize Grammar Teaching in the 21st Century?[END_REF], cf. Römer 2005: 245). Likewise, though negated progressives remain marginally less frequent in textbook dialogues than in BrE conversation (see 3.2.3), the difference is not as striking as in Römer's data (2005: 250). As observed by Römer (2005: 252), progressives in interrogative contexts were found to be overrepresented in textbook dialogues (see 3.2.4). As for the function of progressives, Römer (2005: 262) concluded that progressives that express repeated actions and states were comparatively rare in textbook dialogues. Though more frequent than in Römer's data, the present results confirm that they remain underused (see 3.3.3). The noncontinuous function of the progressive follows the same trend (see 3.3.2). Finally, like Römer 267), there is still a strong tendency to emphasise the framing function of the progressive, even though it only represents a rather marginal function in naturalistic spoken BrE (see 3.3.4).

RQ5 was addressed by comparing the results of two progressive vs. non-progressive Distinctive Collexeme Analyses (DCAs). Some of the differences in the lexis of progressives were attributed to textbook authors' attempts to demonstrate typical functions of the progressive (e.g., DO, PLAY and STUDY as activity verbs, WAIT as a framing verb), as well as textbook task effects (e.g., WEAR, SMILE, STAND in the context of picture description tasks). Other differences were traced back to an overrepresentation of phrases typical of the early stages of EFL instruction (e.g., I come from), the distinct underrepresentation of phrasal verbs (e.g., COME OUT/BACK/UP, cf. Le Foll to appear on the underrepresentation of phrasal verbs with MAKE) and discourse-structuring phrasemes featuring the progressive in textbook conversation (with verbs such TALK, TRY, THINK and SAY). In addition, some stative verbs were found to be more strongly associated with nonprogressive constructions in the TCC than in Spoken BNC2014 (e.g., WANT, LOVE), thus showing that textbook authors foremost feature prototypical uses of the progressive.

Before turning to some potential implications of these results, a few words regarding the study's limitations are in order. First, the choice of a BrE reference corpus may reasonably be questioned. As has already been argued in 2.1, the Spoken BNC2014 bears the advantage of, to date, being the largest corpus of spontaneous everyday conversation by native speakers of English. Although the situation is no doubt evolving, for now, BrE remains the de facto target norm in the majority of European secondary schools. Indeed, aside from individual texts and more rarely chapters, is the first variety of choice in the textbooks of the TEC. Further research avenues, however, could consider comparing the present results with a corpus of spoken American English and/or of proficient speakers of English as a Lingua Franca.

Second, in line with [START_REF] Römer | Progressives, Patterns, Pedagogy: A Corpus-Driven Approach to English Progressive Forms, Functions, Contexts, and Didactics[END_REF] early study on progressives in textbook's representations of spoken language, the present study focuses exclusively on the representations of the progressive in just one textbook register: conversation. Controlling for register was crucial for the results to be meaningful; however, further studies may consider exploring additional text registers (Le Foll forthcoming examines progressives in textbook fiction), as well as textbooks used in other countries and educational contexts.

Finally, the results of the collostructional analysis are subject to the obvious limitation that such a method based solely on verb lemmas cannot account for verb polysemy and phrasal/prepositional usage. In the case of the verbs discussed in 3.4, all quantitative results emerging from the DCAs were carefully checked by searching and examining the relevant concordance lines. For instance, all 111 occurrences of LET in the progressive were manually checked across the entire Spoken BNC2014 to ensure that the observed difference in progressive vs. non-progressive usage was not due to conversations from the reference corpus revolving around renting out property (admittedly an unlikely topic for secondary school textbooks!): in fact, only four out of the 111 occurrences were not progressive uses of LET in the sense of ALLOW. For other verbs, the results were less clearcut: for example, SEE in the progressive was found to be used both in its metonymically motivated sense of MEET or DATE, as well as a verb of sensory perception in both the Spoken BNC2014 and the TCC. The issue of polysemy is even more thorny where the comparison of the DCAs did not reveal any noteworthy differences. Here, however, the fact that the full datasets were manually annotated proved helpful to detect any uncovered patterns related to the different senses of high-frequency polysemous verbs. One such discerned pattern concerns the verb GO, which is not featured on either

Implications and conclusion

In light of these results and limitations, we may therefore ask, on the one hand, which of the differences noted in the use of progressives in textbook vs. naturalistic BrE conversation may be pedagogically well-founded and, on the other, which might deprive learners of valuable exposure to frequent forms with particularly useful communicative functions. Compared to most earlier studies on textbook English, including [START_REF] Römer | Progressives, Patterns, Pedagogy: A Corpus-Driven Approach to English Progressive Forms, Functions, Contexts, and Didactics[END_REF], a major strength of the present corpus design and study is that all the results were controlled for potential effects due to the range of textbook proficiency levels featured in the corpus (A1 to B2). Hence, throughout the discussion of the results, it was made clear that many of the observed differences are probably pedagogically well-founded. This was shown to be particularly the case for most of the reported differences in terms of tense form and time reference distributions. For instance, even though it is true that present perfect and past perfect progressives are overrepresented in level D and E textbook dialogues compared to the Spoken BNC2014 sample, these are complex verb forms that learners may need extra exposure to in order to fully acquire them. Similarly, it may also be argued that since question syntax poses a lot of problems for EFL learners, an overrepresentation of interrogative progressives may also serve a sound pedagogical purpose. In contrast, learners' lack of exposure to key functions of the progressive such as to refer to habits and repeated actions could lead to genuine difficulties in listening and reading comprehension.

In addition, the results have shown that, in authentic BrE conversation, progressive constructions are very often featured in relatively fixed discourse-structuring phrasemes signalling turn-taking, backtracking, helping to clarify misunderstanding, or used as fluency-enhancing strategies (e.g., I'm thinking, she was saying, what I'm trying to say is).

Previous research has shown that individual stative verbs are becoming increasingly frequent in the progressivechief among them, THINK -, as well as progressives phrasemes expressing tentativeness or politeness (I was hoping, I'm wondering) [START_REF] Rautionaho | Recent change in stative progressives: a collostructional investigation of British English in 1994 and 2014[END_REF]. We may thus speculate that, to a certain extent, some of the differences observed between the textbook and naturalistic BrE conversational data are due to textbook authors not taking account of recent language change. However, given that these highly frequent phrasemes fulfil important discourse functions, their notable underrepresentation can be problematic if English learners are to be equipped with the means to successfully communicate in spontaneous conversation (cf. [START_REF] Gilmore | A Comparison of Textbook and Authentic Interactions[END_REF][START_REF] Carter | Spoken Grammar: Where Are We and Where Are We Going[END_REF]. We know that "mastering a language requires the specific, usage-based learning of a vast array of conventional units" (Langacker 2008: 25) and we have seen that, in natural conversation, the progressive construction offers a convenient set of such units that could easily be integrated in textbook dialogues.

The results of the present study confirm Römer's (2005: 284) earlier conclusion that the dialogues of EFL "coursebooks provide a rather monolithic view of what progressives can express". A number of observations, such as the qualitative differences noted in the kind of negated and question-form progressives and the absence of highly frequent discoursestructuring phrasemes, suggest that the world depicted in textbooks remains largely "safe, clean, harmonious, benevolent, undisturbed, and PG-rated" (Wajnryb 1996, cited in We have seen that, at lower proficiency levels (as in (55)), the observed differences between the use of progressive in textbook and naturalistic BrE conversation are largely justified because they simply reflect the prototypical usage of the construction, which, in the didactic reduction of such a complex grammatical phenomenon as the progressive, ought to feature prominently. The present study, however, has shown that most of the observed trends are stable across all the proficiency levels represented in the TCC (cf. Le Foll to appear on how similar patterns have also been observed for other lexicogrammatical features). We may conclude that the present results lend support to Hundt & Vogel's hypothesis that instructed EFL learners' overuse of the prototype of the progressive construction and underuse of its additional functions may be (at least partially) materials-induced.

Excerpts ( 56) and ( 57) demonstrate how authentic conversational data can easily be adapted for pedagogical purposes for intermediate learners and above. For example, in (56), learners' attention can be drawn to the semantic difference between the progressive . 29 form he's putting vinegar on his sandwich referring to an immediate action happening at the time of speaking and, for the generally valid factual statement, the vinegar salts the sandwich, the use of a non-progressive construction. Excerpt (57) could be adapted to demonstrate how meaning can be successfully negotiated among speakers. It begins with an odd-sounding phrase: I must say this is very nice me, which is not readily understood by one of the interlocutors. In negotiating its meaning, the other two speakers resort to a series of progressive constructions highly typical of spontaneous conversation. Adequate exposure to conversational phrasemes such as those featured in (57) can contribute to developing learners' idiomaticity and fluency. It is also known that, for language learning to be most effective, "this exposure should [ideally] occur in the context of meaningful exchanges approximating socially and culturally normal usage events" (Langacker 2008: 25). The snippets of real conversations quoted in ( 56) and ( 57) illustrate how corpus-informed materials may help learners acquire a deeper understanding of complex constructions such as the progressive: starting from its prototypical usage with activity verbs referring to actions happening at the point of speaking and, as learners gain in proficiency, moving to less prototypical usage cases, e.g., with stative verbs, to express repeated actions, and within certain formulaic discourse-structuring phrasemes (cf. Niemeier 2017: chap. 6 on cognitive approaches to teaching aspect in English; Meunier 2008 on combining corpus and cognitive linguistics for language pedagogy). Needless to say that the case for corpus-informed teaching materials has long been made (see, e.g., [START_REF] Mindt | Sprache, Grammatik, Unterrichtsgrammatik: futurischer Zeitbezug im Englischen (Schule und Forschung)[END_REF] for such an early plea; Conrad 2000 on how corpora could "revolutionise" the teaching of grammar); however, the present study has shown that the nine textbook series under studyrepresenting pedagogical materials currently in use in secondary EFL classrooms in three European countriesdo not expose EFL learners to the full range of salient forms and functions that progressive constructions typically fulfil in natural conversation.

Fig. 1 :

 1 Fig. 1: Association plot comparing the progressive form distributions in the Spoken BNC2014 sample and the TCC

Fig. 2 :

 2 Fig. 2: Association plot comparing the progressive tense forms across the five textbook levels of the TCC (see Appendix 1) and the Spoken BNC2014 sample

Fig. 3 :

 3 Fig. 3: Association plot of the distribution of time references of progressives in the TCC and the Spoken BNC2014 sample (excluding progressives with 'unclear' time reference)

  s not skinny either like her mum's a middle aged woman she's carrying a bit of weight around her stomach but she doesn't she's not fat but she's not skinny <BNC2014: SAMQ> (21) but when you're earning what I'm earning there's no way I'm paying off five hundred pound is there <BNC2014: SJLT>

Fig. 4 :

 4 Fig. 4: Comparison of the standardised CollStr values (scaled and centred G 2 ) returned by the two progressive vs. non-progressive Distinctive Collexeme Analyses (DCAs). Positive values represent attraction to the progressive, negative to the non-progressive construction.

  about a book? Oliver: No, I don't think that's a good idea. <TCC: Access 1> (41) I didn't like Celtic music before because I thought it was too fast and repetitive. <TCC: Hi There 6 e > (42) Frank Sinatra? Did he write the song? Hmmm... I think so...? I know he sang it. <TCC: Piece of Cake 5 e > (43) Hi, it's me. Where are you? -Right. Listen! I'm at home. Why don't you come over? There's something interesting, I think. <TCC: Hi There 6 e >

Table 1 : List of the manually annotated functional variables (derived from Römer 2005, 2006) with examples from the TCC and SpokenBNC2014 sample.

 1 Hello, good morning, my name is James Williams, and I'm calling about the basketball coach ad. <TCC: Piece of Cake 4 e > General validity her mum's a middle aged woman she's carrying a bit of weight around her stomach but she

	Continuousness
	Are you still using the computer?
	Yes Mom, but I'm almost done! <TCC: Piece of Cake 6 e >
	Non-continuousness
	Well I said to your dad are you going up again? And he said well not next week but maybe the
	week right after <BNC2014: SA2J>
	Repeatedness/habits

Lisa is here, too. In the music shop? You aren't buying CDs again, are you? <TCC: Green Line 2> Oliver: So, Paul, I didn't know you played the guitar. When did you start playing? Paul: Erm, I've been playing for about five years. <TCC: Access 2> Non-repeatedness doesn't she's not fat but she's not skinny <BNC2014: SAMQ> Politeness or softening But your warm, generous father is unlikely to want to support the project, and I was wondering how to finance it. <TCC: New Bridges 2 e > I was hoping it might be in slightly better condition than that <BNC2014: SA2J> Emphasis/shock Mrs T: Not bad, Sam. Lake Windermere is the largest lake in England, but I'm asking about all of Great British. You mean Scotland and Wales too, Miss? <TCC: Access 2> That's hard. You're telling me! <TCC: Hi There 6 e > Gradual change/development yeah think it'll be alright is that the butter? yep it is wow I'm getting really hungry now <BNC2014: SB9K> Framing I had a terribly embarrassing experience once when I was trying to buy a rail ticket in France. <TCC: Solutions Intermediate Plus>

Table 2 : Contingency table for SAY in the TCC SAY as the main verb of a FVP FVPs with main verb other than SAY

 2

	Row totals

Table 3 : Contingency table for SAY in the Spoken BNC2014 sample SAY as the main verb of a FVP FVPs with main verb other than SAY

 3

	Row totals

Controlling for the total number of FVPs allowed for a better comparison of the results of the two parallel DCAs because the log-likelihood ratio (G 2 ) association measure which was chosen as the basis of the CollStr calculation is highly sensitive to sample size (like other association measures, see e.g.,

Gries 2019b: 388-390)

. The results of the two DCA were first analysed individually. Then, the CollStr values were standardised and visually compared by means of a scatterplot.

All quantitative analyses were supplemented with extensive close reading of the relevant concordance lines, examples of which are given throughout the following results and discussion sections.

Table 4 : Distribution of progressive tense forms

 4

		Spoken BNC2014 sample,	Textbook Conversation,
		N = 2,423	N = 2,423
	past	705 (29%)	381 (16%)
	perfect	109 (4.5%)	157 (6.5%)
	present	1,518 (63%)	1,833 (76%)
	modal	91 (3.8%)	52 (2.1%)
	Pearson's χ

2

(3) = 145.57, p < 0.001, Cramér's V = 0.173

Table 5 : Distribution of progressive tense forms across the five proficiency levels of the TCC (level A = first year of EFL in lower secondary school, level E = fifth year, see Appendix 1) as compared to the Spoken BNC2014 sample

 5

		Level A,	Level B,	Level C,	Level D,	Level E,	Spoken BNC2014,
		N = 316	N = 565	N = 622	N = 577	N = 343	N = 2,423
	past	1 (0.3%)	84 (15%)	130 (21%)	114 (20%)	52 (15%)	705 (29%)
	perfect	0 (0%)	3 (0.5%)	63 (10%)	61 (11%)	30 (8.7%)	109 (4.5%)
	present	314 (99%)	476 (84%)	421 (68%)	385 (67%)	237 (69%)	1,518 (63%)
	modal	1 (0.3%)	2 (0.4%)	8 (1.3%)	17 (2.9%)	24 (7.0%)	91 (3.8%)
	Pearson's χ

2 (15) = 373.52, p < 0.001, Cramér's V = 0.16

Table 6 : Full and contracted forms of the progressive in the Spoken BNC2014 sample and across the nine textbook series of the TCC Contracted Full

 6

	Spoken BNC2014 sample (N = 2,423)	1,285 (53%)	1,138 (47%)
	TCC: Access (N = 418)	226 (54%)	192 (46%)
	TCC: Achievers (N = 101)	43 (43%)	58 (57%)
	TCC: English in Mind (N = 242)	138 (57%)	104 (43%)
	TCC: Green Line (N = 139)	60 (43%)	79 (57%)
	TCC: Hi there (N = 213)	94 (44%)	119 (56%)
	TCC: Join the Team (N = 119)	35 (29%)	84 (71%)
	TCC: Green Line New (N = 1409)	182 (44%)	227 (56%)
	TCC: Piece of cake (N = 163)	64 (39%)	99 (61%)
	TCC: Solutions (N = 619)	283 (46%)	336 (54%)

Table 7 : Negated and non-negated progressives

 7

	Form	Spoken BNC2014 sample N = 2,423	Textbook Conversation N = 2,423
	negated	157 (6.5%)	123 (5.1%)
	non-negated	2,266 (94%)	2,300 (95%)
	Pearson's χ

2

(1) = 4.13, p < 0.001, φ = 0.03 . 14

Table 8 : Interrogative and non-interrogative progressives

 8

	Form		Spoken BNC2014 sample N = 2,423	Textbook Conversation N = 2,423
	question		276 (11%)	434 (18%)
	statement	2,143 (88%)	1,989 (82%)
	unclear		4 (0.2%)	0 (0%)
	(10)	Are you swimming in the sea? Are you playing golf in the jungle?
		<TCC: Achievers A2>
	(11)	Jenny: What are you doing?
		Terry: I'm watching TV.
		Jenny: Why are you watching TV? You usually play football on Saturdays.
		Terry: But it's raining. <TCC: Piece of cake 6 e >
	By contrast, questions in the progressive in the Spoken BNC2014 are frequently rhetorical
	(12) or serve to ask for clarification or confirmation (13)-(14), and often do not follow the
	inverted question syntax featured in the school syllabi (14).
	(12)	okay get it recorded I'm guessing? yeah excellent no one is actually listening to this picking
		out words okay? <BNC2014: SG87>
	(13)

Excluding 'unclear': Pearson's χ 2 (1) = 40.38, p < 0.001, Cramér's V = 0.09 Textbooks feature many more closed questions in the progressive (10) and questions in the progressive usually query what is happening right now, even in cases where the context of a shared environment probably ought to render this unnecessary (11). isn't she having another baby? <BNC2014: SJDM> (

14

) you're not buying dodgy tablets off ebay or anything? <BNC2014: SPZR> . 15

Table 9 : Active and passive progressives

 9

	Voice	Spoken BNC2014 sample, N = 2,423	Textbook Conversation, N = 2,423
	active	2,399 (99%)	2,409 (99%)
	passive	23 (0.9%)	14 (0.6%)
	unclear	1 (<0.1%)	0 (0%)
	Excluding 'unclear': Pearson's χ 2 (1) = 1.75, p < 0.186, Cramér's V = 0.02

Table 10 : Distribution of progressive time reference

 10

	Time reference	Spoken BNC2014 sample N = 2,423	Textbook Conversation N = 2,423
	past	687 (28%)	396 (16%)
	past/present	111 (4.6%)	169 (7.0%)
	present	855 (35%)	1,301 (54%)

Table 11 : Progressives referring to repeated and non-repeated actions or states

 11

	Function	Spoken BNC2014 sample N = 2,423	Textbook Conversation N = 2,423
	non-repeated	1,679 (69%)	2,001 (83%)
	repeated	501 (21%)	394 (16%)
	unclear	243 (10%)	28 (1.2%)

Excluding 'unclear': Pearson's χ 2 (1) = 30.52, p < 0.001, φ = 0.082

Table 12 : Progressives in the TCC and the Spoken BNC2014 sample coded for additional functions

 12

		Spoken BNC2014	Textbook	Association test
	Function	sample	Conversation	(~ function +
		N = 2,423	N = 2,423	corpus)
	emphasis/shock	40 (1.7%)	37 (1.5%)	χ 2 (1) = 1.1, p = 0.29, φ = 0.06
	framing	45 (1.9%)	98 (4.0%)	χ 2 (1) = 19.56, p < 0.001, φ = 0.24
	gradual change	66 (2.7%)	47 (1.9%)	χ 2 (1) = 9.55, p < 0.005, φ = 0.17
	politeness/softening	8 (0.3%)	4 (0.2%)	χ 2 (1) = 1.36, p = 0.24, φ = 0.08

Table 13 : Most significantly distinctive collexemes associated with the progressive (positive G 2 values) and the non-progressive constructions (negative G 2 values) in the TCC and the Spoken BNC2014

 13

  Table 13) because they are often found in such picture descriptions (35).

	(34)	Partner B: Answer Partner A's questions about pictures 1-3.

Use short answers (Yes, he is. / No, he isn't., etc.). Then go back to page 110. A: In picture 1: is the boy drinking? B: No, he isn't. A: Well, is he ...? <TEC: Access 1> (35) In the first photo, I can see a big crowd of people in a very wide street. They're standing on the pavement and they're watching a parade. […] They are walking towards us. They're wearing raincoats and boots. <TCC: Solutions Pre-intermediate>

  Table13or Fig.4. Over the course of the manual annotation and interpretation of the results of the DCAs, it became clear that a substantial proportion of progressive forms of GO in natural BrE conversation result from colloquial, quotative uses of the verb. This is not reflected in the CollStr values reported in Table13because, although quotative uses of GO are entirely absent from the TCC, GO is one of the textbook authors' verbs of choice for progressives with future time reference (see 3.3.1). These observations confirm the need to combine quantitative and qualitative methods to identify patterns that may have practical, in the present case, pedagogical implications.

(54) so then people are like oh so what are we gonna do instead? and people start suggesting things and and are getting really tetchy then cos people are kind of like taking over or sort of saying you know like one person will say something and if a few people like it you've suddenly got a whole group of people that are going oh yeah we should definitely do this <BNC2014: S2C9>

  Timmis 2016: 5). Excerpts such as (55), featuring polite back-and-forth questioning with activity verbs in the progressive referring to what is happening at the time of speaking, serve to show that, aside from an increased use of contracted auxiliaries,[START_REF] Römer | Progressives, Patterns, Pedagogy: A Corpus-Driven Approach to English Progressive Forms, Functions, Contexts, and Didactics[END_REF] concerns with the way progressives are presented in textbook dialogues have seemingly not yet been taken on board by textbook authors, editors and publishers. Let's make some sandwiches.Archie: OK. There's some ham in the fridge. Molly: Are there any tomatoes? Archie: Yes, they're on the table. But there aren't any onions. Molly: That's OK. I don't like onions.

	(55)	Molly: […]

Archie: What are you doing? Molly: I'm putting some salt in my sandwich. Archie: That isn't salt. It's sugar! <TCC: Solutions Elementary>

Rautionaho & Deshors (2018: 236) report that they attempted to include lemma as a random effect variable but that the model did not converge.

Many thanks to Tatjana Winter for her meticulous annotation work and insightful comments, which helped improve the procedure.

In these and the following examples, progressive verbs have been highlighted in bold. The code between the angle brackets corresponds to the name of the corpus from which the example was taken; that is either the Spoken British National Corpus 2014 (BNC2014) or the Textbook Conversation Corpus (TCC), followed by either the conversation ID for the BNC2014 or the title of the textbook volume for extracts from the TCC (see Appendix 1).

The following Sketch Engine CQL query was used to arrive at these frequencies: [word="I"] [lemma="be"] [lemma!="not"] {0,2} [word="thinking"]. It allows for small variations on the phraseme such as I'm/am/was just/yeah/er/like/kind of thinking, but excludes negated forms which do not fulfil the same discourse function.

Acknowledgments

I would like to thank Dirk Siepmann, Peter Uhrig, attendees of the ICAME40, the two anonymous reviewers and the editors of the present volume for their many insightful comments and feedback on earlier versions of this paper. The usual disclaimers apply.

Appendix

To be able to compare pedagogical materials used in different educational systems, each textbook was labelled for proficiency level on a universal scale of A to E: level A textbooks correspond to the first year of EFL instruction at secondary level, in other words, beginner level to roughly A1 on the CEFR scale (Council of Europe 2020), whilst level E corresponds to the fifth year (CEFR B1-B2). Note that French textbook series only cover the first four years of secondary school (which take place at Collèges), which is why, whenever possible, a textbook from the same publisher corresponding to the fifth year of instruction (the first year of Lycée) was added. At the time of corpus compilation, Le Livre Scolaire did not produce any textbooks for Lycées.

The full bibliographic metadata is available on doi.org/10.5281/zenodo.4922819.