Julien Subercaze
email: julien.subercaze@univ-st-etienne.fr

Chaudron

Extending DBpedia with measurement

Keywords: Wikipedia, Extraction, DBpedia, Measurement, RDF, Formal Grammar 10

Introduction

Wikipedia is a free content internet encyclopedia, currently the largest encyclopedia with more than five million articles in its English version; overall 38 milllion articles in over 250 languages. Wikipedia is currently in the top ten of the most viewed websites in the world, with, on average 18 billion page views and nearly 500 million unique visitors per month.

As a central knowledge repository on the Web, Wikipedia serves as a seed for the creation of knowledge bases such as Google's Knowledge Graph or Wolfram Alpha. The Intelligence in Wikipedia project [START_REF] Daniel S Weld | Intelligence in wikipedia[END_REF] used Wikipedia to derive an ontology [START_REF] Wu | Autonomously semantifying wikipedia[END_REF] and fostered open information extraction [START_REF] Wu | Open information extraction using wikipedia[END_REF]. The linked open data movement has long understood the central role of Wikipedia in the web of knowledge. The DBpedia effort is, since 2007, an open source project that aims at translating entries from Wikipedia into RDF and making it publicly available [START_REF] S Ören Auer | Dbpedia: A nucleus for a web of open data[END_REF]. Another extraction of Wikipedia into RDF was made in the Yago project [START_REF] Fabian M Suchanek | Yago: a core of semantic knowledge[END_REF] using a heuristic based approach [START_REF] Kasneci | The yago-naga approach to knowledge discovery[END_REF]. After a tentative to create a semantic backend for Wikipedia [START_REF] Kr Ötzsch | Semantic mediawiki[END_REF], the same authors created a new Wikimedia project, entitled Wikidata [START_REF] Vrandečić | Wikidata: A new platform for collaborative data collection[END_REF][START_REF] Vrandečić | Wikidata: a free collaborative knowledgebase[END_REF], that aims at structuring Wikipedia data in order make them machine readable.

Triples in the DBpedia dataset are mainly extracted from Wikipedia dumps through the DBpedia Information Extraction Framework (DIEF for the rest of the paper). This framework uses manually defined mappings to transform Wikipedia semi-structured content -called Infoboxes -into structured content. These mappings encompass, among others, the structuration of physical measurements intro RDF triples. A measurement is the assignment of a number to a property of an object or an event. For instance, the fact that Lionel Messi is 1.70 meter tall is written as follows in DBpedia: @prefix dbr : < http :// dbpedia . org / resource / > . @prefix dbo : < http :// dbpedia . org / ontology / > . @prefix dbd : < http :// dbpedia . org / datatype / > . dbr : Lionel_Messi dbo : Person / Height "170"^^dbd : centimeter . dbr : Lionel_Messi dbo : Height "1.70"^^xsd : double .

The DIEF, while providing one the most valuable asset to the LOD cloud [START_REF] Schmachtenberg | Adoption of the linked data best practices in different topical domains[END_REF], is not perfect: 40% of the property occurences are unmapped, leaving room for focused automated mappings. Some mappings do not include units [START_REF] Lefranc | Supporting Arbitrary Custom Datatypes in RDF and SPARQL[END_REF][START_REF] Wienand | Detecting incorrect numerical data in dbpedia[END_REF] or some are incorrect 1 and transcluded Infoboxes are not properly managed, especially in chemistry2 [START_REF] Murray-Rust | Chemistry for everyone[END_REF].

In this paper, we tackle the issue of structuring measures from Wikipedia Infoboxes into RDF, where the property is a physical quantity. We take into account the above mentioned issues and design a novel approach that aims for robustness. The contributions of this paper are threefold. First, we extract and make public Chaudron, a dataset of over 900.000 measurements of the utmost practical interest that complements DBpedia. Second, to create this dataset, we devised a novel robust approach based on a formal grammar for units detection. Third, we show that processing rendered HTML is a viable approach for extracting triples from Wikipedia.

The paper is organized as follows: Section 2 presents measurements and how measurements are managed in Wikipedia's Infoboxes. Section 3 describes Chaudron's extraction techniques. Section 4 presents the Chaudron dataset and its characteristics. Section 5 describes the dataset availability and its potential applications. The quality evaluation of the dataset is presented in Section 6. Section 7 provides the concluding remarks.

Measurement

Measurement is, the assignment of a number to a characteristic or event, which can be compared with other objects or events [START_REF] Elazar | Measurement, design, and analysis: An integrated approach[END_REF]. To facilitate comparisons in various fields, measurement systems have been developed. Altough large progress have been made towards unification, there still exists various measurement systems used to describe similar physical dimensions. The metrication -the process of converting to the metric system of units of measurement, also known as the International System of Units (ISU) -began in France after the revolution and spread across the globe. Nowadays, except the metric system, the US customary units and the burmese units of measurement are heavily used in the United Sates and Burma respectively. Due to the large volume of trade between the United States and Canada, the US customary is also in use in some limited contexts in Canada, mainly agriculture and engineering. Altough United Kingdom officially uses the metric system, imperial units is widespread among the public; commonwealth countries are currently in similar situations. Furthermore, non standard units are also widely used in some special contexts or areas. Computer scientists, for instance, are common users of the rack unit -one rack (U) being 44.45 mm -that is used to measure rack-mountable computer equipment such as servers or network elements. In conclusion, there exists a large body of custom units, thus they should be catered or converted accordingly.

This diversity of units system, each of them used by large number of people on earth, is reflected in Wikipedia's articles. In its english version, height, length and the weight are usually displayed in both ISU and US customary units. Non-standard units also appear in Wikipedia articles. This leads to the first challenge in this study, i.e., to identify the set of units that are possibly used in Wikipedia Infoboxes. We adress this issue in Section 3.2. We first start with how measurement are described within these Infoboxes.

Measurement in Wikipedia's Infoboxes

Wikipedia contains a large number of measures, most of them are stored in Infoboxes. An Infobox is a Wikipedia template that is used to represent a summary of the article, as stated in Wikipedia's documentation. It presents a summary of the most relevant facts in form of key-value pairs that are displayed as a table. Units are mainly from the three most common systems of units (ISU, US customary & Imperial) and may include other customary systems. In some rare cases, other unit systems may be used. These cases are sufficiently rare to be ignored. As noted by the authors of DBpedia [START_REF] Lehmann | Dbpedia-a large-scale, multilingual knowledge base extracted from wikipedia[END_REF], most of the editors do not follow the recommendations and good practices for formatting. As a consequence, the units chosen for display are not necessarily standards and may belong either to the three main systems, as well as isolated units of measure that are specialized in some domains. We investigated how measurements are stored and displayed in Wikipedia's Infoboxes. From our experience, they are pigeonholed in three categories: This template allows to display a measurement with two units. It is mainly used to display measurement in both metric and Imperial or US customary systems. The main syntax is the following : {{Convert|val|unit source |unit dest }}.

For instance the following expression {{Convert|1|lb|kg}} gives "1 pound (0.45 kg)". The {{Convert}} template supports a closed list of units suitable for conversion. Formatted display The formatted display is used when one does not require a unit conversion. The {{Val}} template formats a measure with units to a readable form. It is also used to display uncertainty in the measurement. The main syntax is the following: {{Val|number|ul=unit code}}. Similarly to the {{Convert}} template, {{Val}} supports a predefined list of units 3 , however it also supports arbitrary units that may be customised by the editor. Free riding When none of the above described templates are used, editors use custom formatting to describe the measurements. This is the less formatted case of all three. Whereas common practice lead to output that are formatted similarly to {{Val}}, edge cases happen where the output does not resemble to any given format.

Some Infoboxes automatically format certain values, i.e., when an editor fills up the template instance with a key-value pair, the template will process the value with one of the two above described templates or formats it along a predefined pattern. Figure 1 depicts this process: the height is processed by the {{Convert}} templates. Other Infoboxes do not support automatic formatting, this is either due to the impractibility of using a single prefix -range of values maybe too large -or due to the lazyness of the Infobox template editors.

Measures Extraction

To extract measures from Infobox, we are facing the following problem: we must determine whether a key/value pair is of the form: <physicalQuantity / numericalValue Unit>. Our approach is divided in three parts. In the first part, we filter the key/value pairs to discard irrelevant entries. This process is described in Section 3.1. In the second part, we apply patterns to the values of key-value pairs for the single unit case. This pattern matching approach requires a list of units to be matched. We detail in Section 3.2 how we obtained such a list of units. In the third part, we develop a novel technique based on formal grammar to match complex units: this robust technique is presented in Section 3.3.

Infobox parsing & Filtering

As stated in the previous section, measures are often displayed by the mean of templates. These latter may be combined with other templates, making the extraction from the markup text a complex procedure. The DBpedia Information Extraction Framework extracts triples directly from the markup. There also exist very convenient tools to programatically access Wikipedia raw data, as well as its edit history [START_REF] Ferschke | Wikipedia revision toolkit: efficiently accessing Wikipedia's edit history[END_REF].

For our process, such an approach based on wiki markup is not suitable. Templates, such as {{Convert}} or {{Val}}, are complex pieces of code from different languages (Lua, PHP) and are subject to changes. Infoboxes may be aliased (e.g. {{chembox}},{{drugbox}}), or transcluded 4 as for instance chemical elements whose Infoboxes are templates from a template 5 . Therefore trying to reproduce the code stack from Mediawiki 6 in another language is overly complex. This is why the DIEF is unable to extract triples from the Infoboxes of chemical elements. To give an insight into this complexity, the Infobox settlement, one of the most used Infobox in Wikipedia, transcludes more than 50 different templates and more than 40 modules. Moreover, these modules and templates may also themselves transclude other modules and templates.

We chose to parse HTML generated code using a local copy of Wikipedia. This method, while less computationally performant, is more robust. To reduce the performance overhead, we first filter the content from the Wikipedia dump using a custom MWDumper 7 filter. Thus, for a page to pass the filter, its Infobox must either contains digits and units from the list (see Sec 3.2) or the template of this Infobox must contains units or refer the templates for conversion or formatted display. The filter only retains the Infobox text and discards the rest of the page. This allows us to drastically reduce the size and the number of entries on our local Wikipedia copy, i.e., from 16 million entries in the original dump to 1.4 million entries. The size of our local database dump is 2GB against 50GB for its original counterpart. Consequently, this speeds up the overall process as compared to processing the whole set of Wikipedia articles.

While processing HTML from the local Wikipedia pages, a second filter is applied on each key/value pair. This filter is activated before the pair is sent to the units extractor. To avoid useless computation, we verify that the value of the key/value pair contains digits, but not only digits: ensuring that a unit is potentially present after the digits. Once this filter is succesfully passed, we try to match the value against the following pattern: numericalValue Unit, where the list of all unit is thereafter defined.

List of Units

In order to apply the pattern matching approach, we need a list of units used in Wikipedia. For this purpose, we extracted the pages contained in the category Units of measurement and its subcategories. These pages are not necessarily only units and outliers have to be discarded. To ensure that we retain only units, we determine if the first sentence of the page validates certain textual patterns (e.g the first sentence contains "is a unit of") or contains a link to unit pages (Unit of measurement, SI units, Derived SI units, etc). Not every unit is linked 4 https://www.mediawiki.org/wiki/Transclusion 5 See for instance the element Iron and its Infobox which is itself an instance of the Infobox element. 6 Mediawiki is the software that powers Wikipedia 7 https://www.mediawiki.org/wiki/Manual:MWDumper Fig. 2: Extracting the list of units from Wikipedia to its respective category, we therefore apply more restrictive patterns on every page to extract a second list of units.

In Section 2, we described the usage of the {{Convert}} and {{Val}} templates. Each of these templates has an associated list of units, that we also process to extract our third and fourth lists. Finally the four lists are merged, and in total, 464 atomic units and their abbreviations are extracted. When available, we also retain the URL of the Wikipedia article that describes the unit. Figure 2 summarizes this process and depicts the fusion process from the different sources.

This list of units allows us to apply a simple pattern matching technique to extract measurements. This technique consists of detecting numerical values followed by one of the unit from the list. This approach covers simple cases where the measurement can be expressed using a single physical dimension like height or weight. However it falls short when the quantity measured is described by a combination of several units. For example the molar mass expressed in g • mol -1 cannot be extracted using this technique.

Extraction with formal grammar

The above described approach only covers simple cases but falls short on multiple complex cases, i.e., when the dimension of the physical quantities are given using a combination of units. For instance the molar heat capacity of a substance is given in kJ/(mol • K). The formula that describes the unit of such a measure follows, by its very nature, a formal grammar. Formal grammars precisely define the structure of valid sentences in a language. Formal grammars are one of the common underlying tools of formal languages such as computer programming languages, but are not expressive enough to describe natural language where ambiguity arise. However there exists some approach to describe natural language using formal grammar such as the Attempto Controlled English [START_REF] Fuchs | Attempto controlled englishnot just another logic specification language[END_REF] that can be used for knowledge representation purposes [START_REF] Fuchs | Attempto controlled english for knowledge representation[END_REF].

Herein we develop a formal grammar that validates whether or not a string is a valid formula. A valid a formula is made up of a single unit or of an arith-metic expression of valid prefix and units couple. The prefixes are the 26 valid prefixes from the ISU. The abbreviations of the seven core units from the ISU as from its derived units 8 are incorporated in the list. Since Wikipedia makes a very large use of conversion to display measurement in both SI and imperial, it is sufficient to extract the data. We defined valid formula to be standard arithmetic formula including parentheses, along with the operators of multiplication and division between (prefix/units) and exponentiation on the units. We give a simplified version of the grammar in Figure 3. This version omits the complicated details required for units that are not made of a single terminal symbol. For example the mole which is abbreviated mol is one of these cases, since its first letter m collides with the letter used for meter. This requires some special treatment in the grammar than do not carry a particular interest to be precisely described here. The complete grammar is available on Chaudron's website 9 .

UNIT |= m | g | K | A | J | F | V | . . . PREFIX |= Y | Z | E | P | T | G | M | . . . OP |= • | / SIGN |= + | - NUM |= (
An input formula is described as valid, if it can syntactically be parsed by the grammar. An example is given in Figure 4 for the ISU definition of the Volt.

Extraction & discussion

The extraction process is run against the rendered HTML pages obtained from the local Wikipedia copy. The HTML is filtered using CSS selectors in order to retain only the Infobox. Afterwards, the Infobox -which is concretely a table in HTML -is parsed to extract keys and values. Values, if not matched by the

• m 2 • s -3 • A -1 .
simple pattern matching described above, are analyzed by the parser obtained from our grammar. If a value is match ced by the parser, the formula is parsed to extract the unit and to determine whether the numerical value represents an interval or not. The representation of intervals is discussed in the next section.

As we stated in Section 2, we aim at identifiying the largest possible set of physical measurement in Wikipedia Infoboxes. This excludes any measurement that uses non standard units. Figure 5 depicts such an example. Fields highlighted in green are candidates to be extracted since they contain standard units. The field highlighted in red contains a measurement using a non-standard unit rounds per minute, that in fact represents a frequency. These measurements could be interesting to extract but they raise some issues. First of all, being non standard, these units do not connect to any existing system and are of limited use to their very context. Second, the notation of these units is also non-standard, i.e. it does not follow a rigorous notation. For instance rounds per minute appears in some articles under the abbreviation rpm; this, under a different context, means rotation per minute which is also a frequency, but of a very different type of events. Therefore these non-standard units -that do not measure physical quantities but are characteristics of some entities -are edge cases that are difficult to handle.

Dataset

The dataset that we obtain by extracting measures from the Infoboxes in the English Wikipedia contains over 900.000 measurements represented in 3.9 million triples. These measures extend existing knowledge for more than 450,000 DBpedia resources. More than 3.000 properties are measured with more than 600 units. Tables 1 and2 present the most encountered units and properties in the dataset. Representation. Representing units of measures and measurement has been largely discussed within the community and several approaches have been proposed [START_REF] Pinto | Revising and extending the units of measure" subontology[END_REF][START_REF] Leal | Rdf vocabulary for physical properties, quantities and units[END_REF][START_REF] Probst | Observations, measurements and semantic reference spaces[END_REF][START_REF] Masolo | Wonderweb deliverable d18, ontology library (final)[END_REF][START_REF] Rijgersberg | How semantics can improve engineering processes: A case of units of measure and quantities[END_REF]. We refer the reader to [START_REF] Rijgersberg | Ontology of units of measure and related concepts[END_REF] for an overview and interesting discussions. The most common issue with these approaches is that they come with closed lists (often large, but closed) of supported units that do not contain the whole set of units of our dataset. Our approach is an open formalism that resembles those used to represent measures using reification to describe the various properties of the measure. For instance, to describe the fact that the Three Gorges Dam has a Nameplate Capacity of 22,500 Megawatts, we obtain the following representation: @prefix dbr : < http :// DBpedia . org / resource / > . @prefix cha : < http :// w3id . org / chaudron / ontology / > . We are able to link the physical quantity measured to the DBpedia resource using cha:DBpediaResource dbr:Nameplate Capacity. This is possible since the key in the key/value pair in the Infobox links to the Wikipedia page Nameplate Capacity.

Our extraction framework also supports the extraction of interval of values. Intervals are commonly encountered in Wikipedia to describe measure that are variable under the context (dimension of soccer field) or could not be precisely measured. To represent the bounds of the intervals in our dataset, we use the following properties: cha:minValue and cha:maxValue.

We also propose an alternative formalism suitable to process custom datatypes, based on [START_REF] Lefranc | Supporting Arbitrary Custom Datatypes in RDF and SPARQL[END_REF]. Using custom datatypes, one could also integrate conversion and calculus at the triple store level. Dedicated libraries to process units are now widely available. For instance, the Java Specification Request 363 led to an implementation 10 of the units and measure API, that is a perfect candidate to be integrated with Jena in order to realize the vision of [START_REF] Lefranc | Supporting Arbitrary Custom Datatypes in RDF and SPARQL[END_REF]. To our opinion this would provide a more adequate solution for units management than extensible SPARQL queries with Javascript [START_REF] Williams | Extensible SPARQL functions with embedded javascript[END_REF].

Availability & Applications

The Chaudron dataset is fully integrated into the Linked Open Data Web. The resources that are qualified with measurements refer to Wikipedia articles and therefore could be directly binded to DBpedia resources. As a linked dataset, our goal is to ensure the best availability and description of Chaudron to ensure its wide adoption. We follow the current practices [START_REF] Alexander | Describing linked datasets[END_REF] to describe and publish our dataset.

License Chaudron is available under the terms of the Attribution-ShareAlike 3.0 license at the following persistent adress : http://www.w3id.org/chaudron/. The dataset is registered at Datahub 11 and described using VoID 12 . We also provide a public SPARQL endpoint, that is available from Chaudron's homepage.

Applications. The Chaudron dataset extends DBpedia in a way that allows new applications to be developed as well as to enhance existing ones. Since measurement concern universal values, the triples do not only extend the english version of DBpedia but the complete set of localized DBpedia versions. Chaudron also fills the gap with Chemistry [START_REF] Murray-Rust | Chemistry for everyone[END_REF] data and leads the way to the development of new applications in this field. DBpedia has been succesfully used as the primary knowledge source for Question answering Systems, especially within the Question Answering over Linked Data workshop [START_REF] Unger | Question answering over linked data (QALD-5)[END_REF]. With the integration of Chaudron, existing Q&A systems will see their performance increased, since Chaudron provides them with triples from the utmost practical interest. Notably, Question Answering systems would be able to answer a new class of queries, that is, queries comparing entities by an attribute, including top-k queries. "What is the heaviest element between Oxygen and Gallium ?", or "What are the ten fastest roller coasters in the world ?" are examples of such questions. More complex questions such as "In which country, the biggest dam of the 19th century was built?", combine knowledge from both DBpedia and Chaudron.

Evaluation

To assess the quality of the dataset, we conducted a thorough evaluation to determine the precision and recall of our approach and compare with other datasets extracted from Wikipedia. We compare our extraction with the one of DBpedia [START_REF] S Ören Auer | Dbpedia: A nucleus for a web of open data[END_REF], and Wikidata [START_REF] Vrandečić | Wikidata: a free collaborative knowledgebase[END_REF]. We previously discussed the construction of DBpedia; Wikidata follows a similar process as Wikipedia: the approach is to crowdsource the data acquisition.

In order to evaluate the quality of the dataset, we manually annotated over 300 statements from Infoboxes over 40 Wikipedia articles of different nature with the objective to maximize the coverage of categories: our evaluation includes vehicles, cities, persons, weapons, celestial objects, regions, buildings, drugs, rockets and others types of articles containing measurement of different nature. These measurements encompass height, weight, force, diameter, boiling point, torque, volume. The goal of this manual evaluation is to cover many types of categories and measurements. The detailed evaluation is open and can be consulted online 13 .

The evaluation was conducted as follows: articles categories (buildings, drugs, weapons, . . . ) were identified and among them 40 articles were chosen. For each article, the fields in the Infobox have been manually identified. For each dataset, we manually identified one of the following situations: the measurement -including its units -is correctly extracted; the measurement is missing; the measurement is incorrectly extracted. For DBpedia, the latter case is very common. That is, measurement is partially extracted, mostly only the numerical value, but the units are missing. Units are sometimes present in the rela- tionship between the subject and the numerical values (height, weight, length) for instance, but in the majority of the cases this crucial information is missing, making the measurement valueless. As stated in the definition given in Section 2, measurement are meant to be compared and thus required units. Without units, a numerical value assigned to a unitless property does not constitue a measurement.

The results of this evaluation are presented in Table 3. Wikidata, with its crowdsourced approach offers a high precision, but the crowdsourced approach shows its limit on the recall. Out of the 311 measures in this evaluation, Wikidata contains only 17, out of which 16 are correct. We believe that this result to the lack of incentive of people to translate measurement into Wikidata. DBpedia uses also a manual approach, that defines translation for given Infobox templates. Therefore the recall is much higher than Wikidata (.289 vs 0.055) but it indicates that there is room for improvement in the manually defined templates. The main issue with DBpedia and measurement is how units are handled. While some properties contain the unit as the rdf:label, most of properties do not include this information. This is the main reason of the low precision (.55) exhibited by DBpedia on this task. Our approach outperforms its competitors on both precision (.976) and recall (.817), naturally F1-score follows. The formal grammar approach proves very robust on the extraction task. The issues encountered are mainly due to the lack of support for measurement precision (using symbol ±) and to multiple values in the same cell. For instance, when an attribute gets different value depending on context: the Tesla S has different electric range depending on the model. This remains an open issue that could be fixed in the next version of Chaudron.

An important remark is that this evaluation has been conducted to cover the largest body of domains containing measurement. However data is not uniformly distributed as shown in the Infobox usage list 14 . For instance, the template Infobox:settlement reaches by far the first place. More precisely, at the time of writing, out the 3.7 millions use of Infoboxes in Wikipedia articles, the top 10 Infoboxes cover more than the half of use in articles. The top 100 covers 84 percents of the total usage. Would we have conducted an evaluation that follows the distribution, we would have had mainly settlements, taxobox and person articles. However, such an evaluation would leave aside complete domains that are of the utmost practical interest.

Conclusion & Future Work

We presented Chaudron, to our knowledge, the first dataset of measurement that extends DBpedia with more than 3.9 million valuable triples. We described the different techniques used to filter and structure measures from Wikipedia Infoboxes into RDF, including pattern matching and formal grammar. The evaluation shows that our automated approach proves very robust on this extraction task and largely outperforms DBpedia and Wikidata. Our representation of measurement, in its n-ary version, offers the opportunity to support custom datatype processing using recent research results [START_REF] Lefranc | Supporting Arbitrary Custom Datatypes in RDF and SPARQL[END_REF].

A side result of this work, nevertheless interesting for other practitioners is to demonstrate the soundness of extracting Wikipedia data from the rendered HTML instead of using Wiki markup. Future work will include the extraction of measurement from Wikipedia's plain text and will benefit from the Chaudron data for validation. Since Wikipedia's text contains way more information than the Infoboxes, we therefore hope to lift a larger body of measurements.

Fig. 1 :

 1 Fig. 1: Example of Infobox that uses the {{Convert}} template to format the height of a person. Here the basketball player Kobe Bryant.

Fig. 3 :

 3 Fig.3: Simplified BNF Grammar of the unit formula checker. *,+ and ? are the standard Kleene operators. The exponentiation is denoted "*", the multiplication • and the division /.

8Fig. 4 :

 4 Fig.4: Simplified parse tree for the SI equivalent of the Volt : (kg • m 2 )/(s 3 • A) using the grammar defined in Figure3. Note that the grammar also parses the equivalent formulation: kg • m 2 • s -3 • A -1 .

Fig. 5 :

 5 Fig. 5: Example of Infobox that contains standard and non standard units

  ' '22 ,500 ' '^^xsd : decimal ; cha : unit ''MW ' '^^xsd : string ; cha : physicalProperty '' NameplateCapacity ' '^^xsd : string ; cha : DBpediaResource dbr : Nameplate_Capacity ] .

Table 1 :

 1 Top units

	Units	Count	Percentage	Measure	Count	Percentage
	m	352,506	37.124	height	138,985	14.637
	km 2	242,423	25.531	elevation	125,345	13.201
	kg	61,202	6.445	areaTotal	110,351	11.622
	mm	45,401	4.781	weight	70,081	7.381
	km	44,763	4.714	areaLand	44,765	4.714

Table 2 :

 2 Top measures

Table 3 :

 3 Evaluation of the measurement extraction task for Chaudron, DBpedia and Wikidata.

	13 https://docs.google.com/spreadsheets/d/1yKFU1MMakEsKF08b3jMNBe4m91SRVXlsG6WXtNTPzlw/
	edit?usp=sharing

The Bowatenna Dam has a dbp:plantCapacity of 40 W instead of 40 MW

See for instance DBpedia resources corresponding to chemical elements, compounds and drugs, e.g. Iron and Nicotine

https://en.wikipedia.org/wiki/Template:Val/list

https://en.wikipedia.org/wiki/Wikipedia:List_of_infoboxes

https://github.com/unitsofmeasurement/ 11 dataset/chaudron [START_REF] Murray-Rust | Chemistry for everyone[END_REF]


Introduction 1

This article is about compatibilities and restrictions within Oceanic nominalized constructions. Regardless of whether a nominalizing affix is required or whether the nominal context is sufficient in itself to license a verb in a noun phrase position, Oceanic languages exhibit various restrictions on the occurrence of specific markers (tense-aspect-mood, negation markers, articles, possessive markers) in phrasal/clausal nominalizations. More often than not, action nominalization (i.e. propositional/activity/state nominalization) goes together with non-finiteness in the verbal domain, as well as with co-occurrence restrictions in the nominal domain (e. g. in the choice of articles). In most languages, however, nominalized clauses partake of both nominal and verbal properties. It is indeed these mixed features, and the variations observed across languages, that make them very interesting to study. Nominalization and deverbalization processes are said to be correlated with hierarchical constraints, and in the last part of this article I will try address the question whether the principles put forward in the literature are justified by the Oceanic data2 . Before I turn to my main topic, however, it is necessary to make some general introductory remarks concerning the main predicative and categorial properties found in most of the languages taken into account in this article.

Predicates in Kanak as well as in Polynesian language are not marked for tense or person. These categories are expressed in the verbal clause by independent morphemes. In verbal phrases, predicates are accompanied by various particles, either preposed or postposed. Among the preverbal particles we find pronominal subjects indicating person, number and clusivity of the subject, tense/aspect markers and negation. The postverbal particles are directionals and, in some languages, other tense/aspect markers. There are, however, a few exceptions to the predicate invariability: (i) In a few cases Polynesian predicates are marked for number and this number inflection is kept in nominalized clauses ( §5). (ii) Some predicates in Kanak languages are inflected depending on the object (object incorporation, or pronominal vs. definite nominal object). Moreover, we find different transitive or applicative suffixes in most Oceanic languages, which may also be kept in nominalized clauses. A further introductory remark concerns the small inventory of overt categories in Oceanic languages. Languages of this family differ in the obligatory presence or absence of expressions of tense, person or illocutionary force. For the time being I will just illustrate this variation by mentioning some striking differences between two related languages:

-In Xârâcùù (Mainland of New Caledonia), there is no obligatory expression for tense or for person in impersonal constructions, but a subject is most often expressed, either as pronoun or as a lexical item. The modern constituent order is SVO, but the ancient order sVO smS is still used in some contexts such as topicalization ("afterthought"), and in this case, a pronominal clitic (s) is obligatorily expressed before the predicate, co-referring with the postposed subject (S), which, in turn, is introduced by the subject marker (sm).

-In East Futunan (Wallis and Futuna), no argument is obligatorily expressed, but verbal clauses are always marked for tense or aspect.

The following text is structured as follows: First of all (Chapter 2), a distinction is drawn between three types of nominalizations, depending on whether an article identifies a nominalization (type 1), whether a preverbal affix signals this categorial status (type 2) or whether both co-occur (type 3). An additional characterization of nominalizations in Oceanic languages is then provided by describing their distribution in terms of syntactic positions and partly also in terms of functions. Chapter 3 provides evidence for the claim that contrary to widespread views tense markers and aspect markers do occur in many Oceanic languages. It will also be shown, however, that there are constraints for individual tense-aspect markers in individual languages depending on a variety of factors. Analogous variation is also found as far as the occurrence of negative markers (Chapter 4) and the marking of grammatical relations (ergative vs. accusative type) are concerned (Chapter 7). Agreement and the occurrence of adverbs do not seem to give rise to restrictions (Chapter 5 and 6). In the final conclusions (Chapter 8), diachronic considerations and typological generalizations will be discussed.

Nominalization : markers and functions

Three types of nominalizations

In most Oceanic languages, there are no restrictions on the predicate function accessibility: any lexical morpheme may be used as predicate and thus combine with tense, aspect and person markers. Lexical items referring to entities, however, only occur in intransitive constructions (1), (2a), and have to be combined with derivational affixes in order to occur in transitive constructions (2b): Xârâcùù (Mainland of New Caledonia)

1.

Kwémwaa nää apuu-döö, kwé mê nê-kwââ. (Comrie and Thompson 2007: 335) in Kanak and Polynesian languages: In the first type nominalizing affixes are used, whereas in second the presence of a specific/definite article is sufficient for the phrasal or clausal nominalizing process (Moyse-Faurie 2007). The presence of possessive expressions is also a clear indicator of a nominalization. The coocurrence of both kinds of markers identifies a third type. In all three cases, however, the nominalized forms may retain certain properties of the verbs they are related to, including tense-aspect markers, directionals, verbal modifiers and agent markers, as we will see below.

The first type (a): In languages with articles (as for example, some of the languages of the Loyalty Islands, Fijian, Western Polynesian languages), an article nominalizes a verb or a verb phrase, a case often also described as zero nominalization. It is the article which bears the referential index, as is now generally assumed in syntactic theory. This is the case in Boumaa Fijian, where Dixon (1988:130-131) points out the obligatory presence of the common article a/na introducing the nominalized clause, which also includes a possessive pronoun, corresponding to the intransitive subject/agent of the verbal clause: Boumaa Fijian (Dixon 1988:130-131)

3.

Au maarau va'alevu i na omudou yaco mai qoo. 'Then comes Tuilekete hitting the wooden bell in the morning.' (Lit. this is then the hitting of the bell by Tuilekete in the morning) The specific article used to nominalize a verbal clause has been analyzed by [START_REF] Vernaudon | De la translation substantivante à la quantification : vers une caractérisation sémantique de l'article te en tahitien[END_REF] as a 'translatif' (in Tesnière's (1959: 80) terminology). In some languages, the non-specific articles may nominalize verb phrases, but the nominalized phrase then loses its reference to an event; it behaves as a type of entity, and cannot be determined by any aspect marker or by a directional or other adverb, as we will see below in §3.2.3.

The second type (b): In Kanak languages of the Mainland, it is the presence of a nominalizing prefix on the verb which marks the nominalization of the verb phrase or of the entire clause. This is shown by the example (5b) from Xârâcùù, contrasting in this point with the verbal clause (5a): Xârâcùù (Mainland of New Caledonia) (Moyse-Faurie 1995:57) 5a.

Nèpôrô mê Tuura mê na. 'The Nèpôrô clan and the Tuura clan have come. ' (Lit. their [past] arrival, the Nèpôrô and the Tuura) In Xârâcùù (Moyse-Faurie 1995:183-190), as in all Kanak languages, there are several nominalizing prefixes, such as: kèè-'way, manner', ù-'place', a-'action', xwâ-'result', xêêpossibility.

The third type (c): Both the article and a nominalizing prefix occur, as in Cèmuhî, where the presence of both the article a and the action nominalizing prefix a-in (6a) contrasts with their absence in the verbal clause (6b): Cèmuhî (Mainland of New Caledonia) (Rivierre 1980:267) 6a. a a-taa-bé tè-lé 6b. Lé taa-bé.

ART NMLZ-go.up-DIR POSS-3PL 3PL go.up-DIR 'their going up here' 'They are going up here.'

An additional characterization of nominalizations in Oceanic languages can be provided by describing their possible syntactic positions within a more complex sentence or their functions as sentence types when they are used as independent sentential units. In two of these cases, (i) and (vii), nominalizations are used as completely independent utterances, in the others a sentence is rank-shifted to the status of a clausal constituent. These uses will now be discussed in more detail.

Range of functions

(i) Nominal clauses: [START_REF] Yap | The development of nominalizers in East Asian and Tibeto-Burman languages[END_REF]Noonan 1997:381), i. e. to signal the speaker's perspective or attitude toward the state of affairs expressed in the clause, has recently been described by Lichtenberk (2011) for Toqabaqita: Toqabaqita (Solomon islands) (Lichtenberk, 2011:715) 23.

Qaa! Ngata-laa sula doo qoro qeri!

INTERJ talk-NMLZ about thing be.many that 'Hey! All this talking about the things.' (Lit. Hey! Talking about those many things)

Different types of exclamative nominal clauses are attested in Oceanic languages, depending on whether the nominalization is part of a larger construction (type 2 and 3) or not (type 1) (see Moyse-Faurie 2011 for more details). The first type is a 'stand-alone' nominal clause, i.e. without any copular or predicative marker. This type may include a nominalizing affix on its head-noun as in the Toqabaqita example ( 23), or it may occur without any nominalizing affix, as in Tokelauan (24). Tokelauan (Hooper 1996:233) 'What a peculiar way of weaving you have!' The head-noun of such bare exclamative clauses may be an overtly derived-noun as in Tuvaluan (25): Tuvaluan (Besnier 2000:40) 25.

Te 'How well these banana trees are growing!' Lit. at the good life of these banana trees)

Tense aspect markers in nominalized clauses

Occurrence of tense aspect markers

Tense-aspect markers are rarely found in nominalized clauses across languages. In fact, it is often said that they are impossible in specific Polynesian languages, as is shown §2.1, starting with Chung (1974:642), who already asserted: "In many PN languages, sentence nominalizations are derived by replacing the tense marker of a sentence with an article and adding a suffix to the verb." [my emphasis] An even more general claim can be found in [START_REF] Naess | A Grammar of Vaeakau-Taumako[END_REF]: "The main feature of decategorization of Vaeakau-Taumako nominalized clauses is the loss of the tenseaspect-mood marker. This is accompanied by a recategorization feature, the introduction of an article or possessive pronoun to replace the tense-aspect mood marker. id. (Lit. is finished has been grated our swamp taro for pudding) And, to give two more examples of pertinent observations on Polynesian languages, Bauer makes the following statement for Maori [my emphasis] "In the nominalization, there is no TAM marker, and the verb base has as a suffix the appropriate form of Canga." (Bauer 1997:517). In Tahitian, according to Lazard and Peltzer (2000: §12.4.1), the suffix -ra'a is normally associated with the nominalization of verbal clauses, the article te replacing the tense-aspect marker. Assertions of this kind are also often made for other Oceanic, non-Polynesian languages. According to Frank Lichtenberk (2011): "the tense distinction and negation are expressed by means of preverbal subject markers, but these do not occur with nominalizations" (Lichtenberk 2011:706). Analogous observations have been put forward for Lolovoli by Hyslop (2001:391): "Nominalised complements convey the same meaning as complement clauses, but they are non-finite".

In view of what is generally found cross-linguistically such observations are not surprising. In many languages, very few verbal features such as tense-aspect markers are retained in nominalizations. But what is it that prevents the occurrence of tense-aspect markers in nominalized constructions? Arguments do retain some of their verbal marking, and directionals or other adverbs are very often part of nominalized clauses. So, why are tenseaspect markers not kept, too? The preceding observations do not provide an explanation for the observed asymmetry between nominal and verbal constructions. If nominalizations refer to events, then these events can certainly be located in time as the following clumsy cases from English show: John's former/future writing of books. The frequently observed restrictions can therefore not be semantic ones. And indeed it turns out that tense-aspect markers do occur in nominalized constructions, at least in some Oceanic languages. On the other hand, this compatibility can only be found in some languages of the same subgroup, while other languages do not manifest it and this distribution of variants poses similar problems for an explanation as the above observation on the total lack of tense marking in nominalizations in specific languages has done. Is this a recent evolution, a way of increasing the parallelism between noun phrase and verb phrase? It would be interesting to understand why there is such a need for more finiteness and thus temporal reference in the nominalizations than is required in most languages. The compatibility of aspect and/or tense markers with nominalization is attested at least in some Polynesian languages, in Fijian and in several New Caledonian languages. We will now present examples of these tense-aspect categories in nominalized clauses, before turning to the constraints that may be found.

a) Past tense

In Xârâcùù, most of the tense-aspect markers, whatever their position in the verb phrase is, may occur in nominalized constructions, as well. The following examples illustrate various syntactic contexts where this possible: Past tense is expressed, in (33), after the intransitive verb, in an independent nominalized sentence, in a nominalized relative clause (34), as well as in an dislocated argument position of a nominalized phrase (35): Xârâcùù

33.

Kèè-mê na rè nyärä Nèpôrô mê Tuura. 'I was able to eat, my teeth were not hurting anymore.' The past tense is also found in nominalizations in Fijian: Fijian (Dixon 1988:132)

36.

Au tadra-a a omu aa la'o mai 1SG dream-TR ART your PST go DIR 'I dreamt that you had come.' According to Krupa (2005:513), who wrote, concerning the following example: "the deverbative is marked with te i [that is, with the specific article + past tense marker], which seems to be statistically rare", the past tense marker is also licensed in nominalizations of Marquesan: Marquesan (Krupa 2005:513) 37.

[ 'When the brothers saw that the mother had nearly reached the top, (then) they cut Hina's hair.'

b) Perfective

The perfective aspect is probably the aspect most often encountered inside of nominalized phrases in other languages.

In Cèmuhî, the perfective aspect can be inserted between the nominalizing prefix and the verb: Cèmuhî (Rivierre, 1980:268) 38. pa a-caa-tupwö olè hê-a-li pwö-n

MSC.ART NMLZ-PFV-fall DIR in-n.ART-DEF hole-POSS3SG
'the man who fell in the hole' The perfective aspect is also found in nominalizations in Polynesian languages, such as Tokelauan 3 Tokelauan (Matagi Tokelau, 1990:62 in Vonen 1993) or in East Uvean:

39.

Na 'One of the men pretended to have died…' 3 Hovdhaugen et al, however, observe that all words of the verb phrase except the tense words are retained when it is transformed into a noun phrase (1989:101) and tense, in this book, also includes aspects such as perfective kua, or progressive koi.

4 According to Lichtenberk, there are no other examples of nominalizations in Toqabaqita occurring with tense/aspect markers. There is, however, reduplication of nominalizations to express continuativity or iterativity, as in fii-fita-laa /RED-run-NMLZ/ 'the runnings' (Lichtenberk 2008: 441, ex. 9-71).

d) Imperfective

The imperfective aspect is found in Tahitian nominalizations, where the article te combines with the imperfective e in a nominalized clause, as in example (13), repeated below: Tahitian (Lazard & Peltzer 2000:83) 43.

Teie 'Here is a photo of Teri'i who will come here in a moment.' The same is true of Samoan, where we find the 'general tense-aspect-mood particle' in a nominalized phrase as a benefactive argument introduced by the preposition ma: Samoan [START_REF] Mosel | Samoan Reference Grammar[END_REF] 'I will stay here until your imminent coming back.'

The preceding examples have shown that (nearly) all tense-aspect categories are also found in nominalizations of some Oceanic languages, a rare and thus remarkable phenomenon in the world's languages.

Constraints

The tense-aspect markers listed above are not found in nominalizations of all Oceanic languages, however. There are constraints depending on a variety of factors.

Let us now turn to these different constraints imposed on the selection of tense-aspect markers in nominalized phrases or clauses and the semantic and/or syntactic properties they might be due to.

One possible, very general hypothesis is that the occurrence of tense-aspect markers is linked to a weak distinction between nouns and verbs. This, however, is clearly not the case, since in New Caledonian languages, where nouns and verbs are clearly distinguished, there are fewer restrictions for tense-aspect in nominalized clauses than in some Polynesian languages, where tense-aspect markers are not allowed at all. I also examined the meaning of the nominalized verbs occurring with tense-aspect, but I found no clear evidence for restrictions. What I found was that different types of constraints exist, depending on the tense-aspect marker itself ( §3.2.1.), or, in some Polynesian languages, either on the presence of a nominalizing suffix on the verb ( §3.2.2.) or on the choice of the article ( §3.2.3.). None of these constraints, however, seem to be linked to the type of the argument structure ( §3.2.4.)

Constraints on the selection of individual tense-aspect markers

As far as the type of tense-aspect markers licensed in or excluded from nominalized constructions is concerned, I did not find any clear systematicity across Oceanic languages. In some Polynesian languages, tense markers cannot occur inside the nominalized phrases or clauses. 'You are a teacher, you?" 'You have been a teacher, you?' In Xârâcùù, it is just the opposite: the perfective marker is not allowed inside the nominalized phrases, whatever the verb valency, while the past marker, as we have seen (33-35) is unproblematic. The perfective marker wâ must occur before the nominalized construction. Xârâcùù

51.

Wâ kèè-coa rè Anik ku.

PFV NMLZ-peel POSS Anik yam 'It is now the way Anik peels yams.' In Fagauvea, as in the other Polynesian Outliers, no tense-aspect markers are licensed in nominalized phrases; Fagauvea, however, allows hano (grammaticalised from the verb 'to go') which conveys a modal value (obligative or irrealis mood), as in (52b.): Fagauvea (Uvea, Loyalty islands, Polynesian Outlier) (A. Djoupa, p.c.) 52a.

Gu de fetali gi de fale-tau ainei de vaka.

1SG IPFV wait OBL SPEC NMLZ-land soon SPEC boat 'I am waiting for the landing of the boat in a few moments.' 52b.

Gu de fetali gi de fale-hano-tau ainei de vaka.

1SG IPFV wait

OBL SPEC NMLZ-IRR-land soon SPEC boat 'I am waiting for the boat which should be landing in a few moments.'

In South Efate, a derived noun, nominalized by the article na-and the nominalizing suffix -wen may include the 'be' copula in its irrealis form (fi): South Efate (Vanuatu) (Thieberger 2006:137) 53.

Na-fi-soklep-wen gar i-top.

ART-be:IR-rich-NMLZ 3PL.POSS 3SG.RS=much 'Their wealth was great.' It seems that this is the only possible tense-aspect-mood occurrence in South Efate nominalized constructions.

The role of affixes

Severe restrictions seem to occur in most Polynesian languages when the nominalization process includes a nominalizing affix. The crucial point here seems to be whether the nominalizing prefix only has a nominalizing function, or whether it also conveys aspectual values, and consequently prevents verbal tense-aspect expressions.Thus in Tahitian, the presence of the nominalizing suffix on the verb prevents the occurrence of the aspect marker. The nominalizing suffix itself conveys a meaning (perfective/resultative) similar to the aspect marker. Tahitian (Poeura Tetoe, p.c.) 54a.

'Ua māere au i tā'oe pahono-ra'a.

PFV be.surprised 1SG OBJ your answer-NMLZ 'I am surprised by your answer.' 54b.

'Ua māere au i tā'oe i pahono(*-ra'a).

PFV be.surprised 1SG OBJ your PFV answer I am surprised by your answer. In East Futunan, tense-aspect markers are not found when the verb is suffixed by -gā: the patient/absolutive argument is just juxtaposed to the nominalized verb, and not expressed as a possessor as is the case without the suffix. As in Tahitian, the nominalizing suffix is sufficient by itself to express a perfective aspectual meaning. East Futunan

55.

Na fai le faka-nofo-gā sau fulumalie PST happen SPEC CAUS-sit-NMLZ king beautiful 'The beautiful investiture of the king has happened.' The same situation is found in Rennell and Bellona verbal clauses , where the suffix 'aŋa is sufficient to convey a past or perfective meaning, as shown in ( 56) and ( 57). Rennell and Bellona (Elbert & Schütz1988:149)

te māsaki-'anga a Moa

SPEC sick-NMLZ POSS Moa 'Moa's (past) sickness.' 57.

Te tā-'anga e Moa toku baka.

SPEC build-NMLZ AGT Moa my canoe 'Moa made my canoe.' (Lit. the has made by Moa my canoe) In ( 57), as it is the case in East Futunan example (55), the absolutive argument of the transitive verb is not expressed as a possessor. With transitive verbs, the suffix both prevents the occurrence of tense-aspect markers, and the expression of the patient in a possessive phrase. In Rapanui also, no tense-aspect is admissible in combination with the -Vŋa suffix, which is described as imperfective ("as yet unrealized") in Du Feu 1996: 178-179). Rapanui (Du Feu 1996:118)

58.

Ko tikea'a e au te tetere-iŋa o raua.

PFV see.RES AGT 1SG SPEC RED.run-NMLZ POSS 3PL

'I saw them all running away.' In Nêlêmwa, the derivation with the shâ-prefix conveys a stative/resultative meaning (59) whereas the -a nominal determiner suffixed to the nominalized verb conveys a prospective or generic value (60). Nêlêmwa (Extreme-North of the Mainland, New Caledonia) (Bril 2002:77-80)

59.

shâ-tilu i na.

NMLZ harvest POSS 1SG 'my harvest.' 60.

Hla vhajamalî u-khabe-a mwa eli.

3PL discuss NMLZ-build-DET house DEIC 'They are talking about the construction of this house.' (prospective)

These examples show that whereas in some languages such as Xârâcùù, the nominalizing prefix only has a nominalizing function, nominalizing affixes in other languages also convey aspectual values, and consequently prevent verbal tense-aspect expressions.

In Tokelauan, however, the nominalizing suffix AND an aspect marker may co-occur, as shown in (61).

Tokelauan [START_REF] Hooper | Type and instance nominalisations in Tokelauan[END_REF]:228, from Vonen 1988) 61.

Ko te ka fano-ga o te tino, na tāofi ai e tētahi tino.

PRED SPEC IMM go-NMLZ POSS SPEC person PST stop ANAPH ERG another person 'On the occasion of the person being about to go, he was held by another person.' Once more, we can observe how difficult it is to make reliable generalizations about the occurrence of tense-aspect markers in nominalized constructions.

Constraints imposed by articles

Further constraints concern the compatibility of nominal determiners as signals of the nominalization and tense-aspect markers. In most Polynesian languages, only the specific article may nominalize a verb phrase, as is the case with le in East Futunan (PPN *te). As already mentioned, the same restrictions occur in Vaeakau-Taumako (cf. Naess & Hovdhaugen 2011:57), and in Tahitian [START_REF] Vernaudon | De la translation substantivante à la quantification : vers une caractérisation sémantique de l'article te en tahitien[END_REF]. In East Futunan or in East Uvean, languages, where aspect markers are allowed in nominalized clauses, other articles than the specific one may indeed nominalize verbal phrases; but then, the nominalized phrase loses its referential quality; it denotes a type of entity, and cannot be determined anymore by any aspect marker, or by any directional adverb. These are then pure cases of lexical nominalizations: East Uvean

62.

Ne 'He voted for Petelo because of the false promises of work that had been given to him'. (*i ni kua ga'oi loi)

The role of argument structure

In my data, I found no differences in the licensing of tense-aspect markers depending on the argument structure of the languages, in contrast to Koptjevskaja-Tamm (1993:160) statement that "very few verbal features are retained in nominalisations of the ERG-POSS type". In the 25 languages of her sample, only one language (Hixkaryana) has tense, and Modern Hebrew and Māori have negation (in Māori, of the nominal type, that is, English no). Among the languages of the POSS-ACC type (25 languages), Māori and Modern Hebrew are again listed as having negation, plus Egyptian, English, Swahili and Turkish; tense is found in four languages (Evenki, Mongolian, Turkish and Tuva), and aspect in English. Among the 17 sentential-type languages5

Negation

, 8 have distinct tense-aspect markers in clauses with action nominalizations (Koptjevskaja-Tamm 1993:255).

As is the case with tense-aspect markers, the admissibility of the negative marker inside the nominalized phrase is variable in Oceanic languages. In some languages the usual verbal negators are admissible, in others only the nominal negators are possible in nominalizations (cf. English not vs. no) and in still others negation seems to be totally excluded from nominalizations.

4.1. Negative markers are allowed. 6Negative particles may occur in nominalized constructions in a number of languages including Tuvaluan (Besnier 2000: 510) '(It is a fact) he doesn't grow kava anymore.' (Lit. It is the not still growing of the kava by him) This is also possible in Tokelauan with hē 'not'as negative marker, or with hēki 'not yet'. Tokelauan (Hooper 1996:228, 3SG to.cause that self-2SG be.tired 'Your being big is not due to your eating too much and to your laziness, it is due to your tiredness.' In Fagauvea, too, the inclusion of the negative marker in the nominalized phrase is possible and frequent. Fagauvea (A. Djoupa; p.c.)

67.

Goi i de moonii-ina (dona) fale-he-numai anaafi a Sinoki.

PROG 3SG NPST be.angry-TR his NMLZ-NEG-come yesterday PERS Sinoki 'She keeps being angry [because] Sinoki didn't come yesterday.' In Samoan, according to Mosel & Hovdhaugen (1992:531) "the nucleus of nominalized verbal clauses is formed by verbs (which can be negated by lē 'not' and modified by prenuclear and post-nuclear adverbs), whereas the nucleus of other noun phrases does not combine with negative particles or adverbs". Samoan (Mosel & Hovdhaugen 1992:531)

68.

Sa ou nofo ma le lē fiafia… PST 1SG stay with ART NEG be.happy 'I stayed there and was unhappy…' (Lit. I stayed there with the not being happy)

Nominal negation only

In Kokota (Palmer 2009: 307ff.) negation "is expressed in two ways: by the use of the negative particle ti and by a subordinating construction involving the negative existential verb teo 'not exist'. The latter is by far the more frequent strategy but the particle ti is the only means of marking negation in nominalized clauses, in manner deixis constructions ('be thus') and in nonverbal predications". The negative marker ti is found in example (69): Kokota (Santa Isabel, Solomon islands) (Palmer 2009:308) 69.

Ka=ia ti mai=na=o=n̄a velepuhi kokota n-e-ke

LOC=the.SG NEG come=3SG.POSS=DEIC=IMM right.away Kokota

Subject plural agreement

In Polynesian languages, there do not seem to be restrictions as far as subject-plural agreement is concerned. Reduplication, as a marker of subject plural agreement, is maintained in nominalizations, as we saw in East Futunan example (46), as well as in Rapanui ( 71 'I know how to fix my car by myself.' Nominalized exclamative clauses often contain focus particles, degree adverbs or emphatic markers, such as Māori hoki, East Uvean leva, as shown by the examples below. Māori (Bauer, 1997: 526)

75.

Te

Arguments in nominalized clauses

Whereas I found no differences in the admissibility of tense-aspect markers in nominalized verb phrases depending on the argument structure of the languages, there are important differences depending on the marking of arguments in the relevant language. [START_REF] Comrie | The syntax of action nominals: a cross-linguistic study[END_REF] noted that among verbal arguments, the subject is the first candidate to receive possessive encoding in nominalized phrases. This is true for accusative languages such as Xârâcùù. In ergative languages, it is the absolutive argument which is coded as possessor8

Ergative languages

, the ergative argument remaining in the ergative case. The expression of arguments in nominalized phrases is thus linked to the encoding of grammatical relations and to the type of valency found in the languages. In the Polynesian ergative languages, the agent arguments in nominalized phrases are expressed either as possessor when the construction is intransitive, or retain their ergative marker when the construction is transitive. In accusative languages such as Xârâcùù, by contrast, the agent is always downgraded as possessor, no matter what the nominalized verb's original valency is and so is the patient in intransitive construction; in transitive construction, however, the patient (former object) remains unmarked.

In ergative Polynesian languages, when only one argument is expressed, it occurs as a possessor, introduced either by the alienable possessive marker (a) if it refers to an agent (78a), or by the inalienable one (o)

Accusative languages

In accusative languages such as Xârâcùù, by contrast, the agent of a transitive verb is downgraded to the status of possessor, while the patient is simply juxtaposed to it, without any marking. This is the case irrespective of the categorical status of object or subject. In the following Xârâcùù example, the second nominalized phrase (kèè-sakwîî…) includes a possessive noun phrase referring to the agent (röö), followed by a free pronoun referring to the patient (gu 'the place of sand shoveling' And when both arguments are expressed, it is the agent which is marked as possessor, while the patient (nâwâ in (82c)) is relegated to the periphery without any specific marking: 82c.

ù-sëi rè wîrî nâwâ

NMLZ-shovel POSS 2PL sand
'the place where you are shoveling sand'

Other cases

In Nêlêmwa, the patient retains its verbal marking and position (object pronominal -yo suffixed to the verb), whereas the agent (na) is expressed as the possessor, in second position. Nêlêmwa (Bril 2002:79) 83.

Hna-kûûlî-a u-axi-yo i na NMLZ-finish.TR-POSS NMLZ-see.TR-2SG POSS 1SG It is the last time I saw you. (Lit. the end of my vision of you) In Fagauvea, different argument markings are possible.

If the nominalized verb is intransitive, the argument is marked as the possessor, whether it refers to an agent or to a patient. Fagauvea (A. Djoupa, p.c.)

84.

Na ia ofo i de fale-hulu o de fofonu i maalefa.

PST 3SG be.surprised OBL SPEC NMLZ-enter POSS SPEC people OBL chiefdom 'He was surprised at the entrance of the people in the chiefdom.' If the nominalized verb is transitive, the object, referring to the patient, keeps its verbal position and marking, regardless of whether the agent is expressed or not.

85.

Gu de sakilia e hele mo de tuakia mala fai atu.

Conclusions

Nominalization is a very productive strategy in Oceanic languages, with a large spectrum of possible uses. Besides the usual functions linked to nominalizations as a result of the syntactic position they fill (arguments, clausal complements), we have seen that nominalized exclamative clauses may be considered as the prototypical expression of exclamation in many Oceanic languages. While adverbs, directionals and emphatic particles are most often kept in nominalized clauses, there are several types of constraints concerning the expression of tenseaspect or negation markers, even though they do occur quite often in nominalized constructions.

In the following final section, I will try to explain the constraints observed, either in terms of historical processes of change or in terms of typological generalizations.

Diachronic considerations

Constraints which are linked to the expression of a nominalizing affix may have a historical explanation. Indeed, in some Austronesian languages (such as Cebuano, cf. Himmelmann 2005:126) focus/voice markers also often convey tense-aspect-mood information, and as suggested by [START_REF] Starosta | The evolution of focus in Austronesian[END_REF], some of these voice markers are derived from affixal nominalizers9 Nominalizer → focus/voice marker → resultative/perfective/anterior , as in Saisiyat:

So we could suggest the following evolutionary scenario: Some languages retained the old aspectual value of the nominalizers and, as a consequence, do not allow tense-aspect markers in their nominalized constructions.

Other languages lost the aspectual value of their nominalizers, or even changed the nominalizing suffixes into new prefixes. Later on, however, whenever aspect or tense had to be expressed in their nominalized constructions, they simply retained what they had at hand in verbal clauses, that is, verbal tense-aspect markers! These two putative developments can be summarized by the following diagram:

⇒ Retention of the old aspectual value of the nominalizers > no tense-aspect markers in the nominalized constructions. ⇒ Loss of the aspectual value of the nominalizers > insertion of verbal tense-aspect markers in nominalized constructions.

Typological implicative hierarchy

The very last point I would like to make is a typological one: Is there any ordering of the features that are acquired or lost during nominalization? I tried to compare my data with some theories establishing a cline of deverbalization / nominalization processes. My data can be summarized in the following The occurrence of a suffix or of the non-specific article and the expression of the agent as a possessor clearly increase the nominal character. Some features, such as the occurrence of a tense-aspect marker, of a specific article or of a nominalizing prefix, by contrast, induce neither a more verbal nor more nominal character. Arguments in nominalized clauses manifest a variable ability to be expressed as possessors depending on the verb valency. If the nominalized verb is intransitive, most languages allow a possessive expression of the argument. When the verb is transitive, by contrast, there is more variability: it may depend on the way grammatical relations are marked in the language, on the syntactic category of the arguments or on the type of the nominalizing strategy.

In the typological literature on nominalization the following implicational hierarchies have been proposed for the constraints observed.

(i) Noonan (1985:57) gives the following implicational hierarchy on the basis of his data: Subject agreement and Mood > Tense > Aspect > Voice, Valency, Object agreement. This scale must be read as follows: the further to the left a category is on the scale, the less likely is it to be encoded on a nominalized complement.

As we saw in § 5, subject verbal agreement is maintained in Polynesian nominalized phrases. On the other hand, tense is not encoded inside nominalized phrases in these languages, even if all the other categories are. (ii) Croft (1991:83) proposes the following "Deverbalization Scale":

Finite TAM retained > S-marking retained > O-marking retained [> means 'implies'] In most of the languages of our data, however, the retention of tense/aspect markers in nominalizations is stronger than the retention of case markers. Nêlêmwa on the opposite, reflects the deverbalization scale proposed by Croft: nominalizations loose the tense-aspectmood categories, but retain valency markers. (iii) Finally, [START_REF] Comrie | Grammatical Categories and the Lexicon[END_REF] note that aspect and voice may be retained in lexical nominalization, tense rarely, and mood and verbal agreement virtually never:

Illocutionary force > mood > tense > aspect As we have shown in this article, the occurrence of tense and aspect markers is attested not only in lexical nominalizations, but is also quite frequent, as far as Oceanic languages are concerned, in phrasal and clausal nominalizations, that is, at the syntactic and discourse level as well. Thus, such implicational generalizations do not fully apply to all Oceanic languages. Moreover, as noted by [START_REF] Malchukov | Remarks on deverbalization[END_REF], these generalizations are not always compatible with each other. Predictions such as the relative susceptibility of agreement and tense-aspectmood categories to get lost are constrained by a semantically (scope and relevance) based hierarchy of verbal categories. For example, "tense affects the meaning of the verb stem less directly than aspect does." He suggests to base such predictions on a hierarchy of verbal categories as established in the functional-typological literature. Finally, I found no instances of Malchukov's final step, that is, "full decategorization involving the loss of all verbal categories", in the Oceanic languages.

  Lexical items referring to states or actions can only occur in a non-predicative function if they are nominalized. There are three types of "action nominalization"

		Kwémwaa	PROG.PST master-earth water and leaf-tree
		'Kwémwaa was the master of the earth, of water and of the leaves.'
	East Futunan
	2a.	E	puloga a au i	aso fuli.
		NPST hat	ABS 1SG OBL day all
		'I wear a hat every day.' (Lit. I hat every day)
	2b.	E	puloga-'i e	au le	puloga o	loku tupuna.
		NPST hat -TR	ERG	1SG ART hat	POSS my	grandfather
		'I am wearing my grandfather's hat.'

  In these languages, nominalizing affixes do exist, but their main function is to derive new lexemes such as concrete deverbal nouns, and they are not used to nominalize an entire clause. The choice of the article used to nominalize a clause or a phrase is often not free. In

		1SG happy	greatly		at ART your		arrive DIR DEIC
		'I'm very happy at your arrival here.'
	East Futunan (Moyse-Faurie 1997:95)
	4a.	Kua tā le	lali e	Tuilekete i	le	usu.
		PFV	hit SPEC bell ERG Tuilekete OBL SPEC morning
		'Tuilekete hit the bell in the morning.'
	4b.	Ko lenā loa le	tā o	le	lali e Tuilekete la	i	le	usu.

most Polynesian languages, only the specific article may nominalize a verb phrase, as is the case with le in East Futunan (PPN *te : Tongan e/he; Samoan le; Tokelau, Tahitian te): PRED DEIC then SPEC hit POSS SPEC bell ERG Tuilekete EMPH OBL SPEC morning

-sùù rè aaxa Pokwé.

	(ii) Relative clauses
	In the range of uses of nominalizations that are encountered in the world languages, the
	attributive function of relative clauses is well attested in Oceanic languages. The relative
	clauses from Xârâcùù in (11) and (12) are nominalized clauses, lit. 'the big wave [which is]
	the pushing result of the Uvean chief' in (11), whereas in the Tahitian example (13), it is an
	identificational clause, introduced by the predicative marker 'o, qualifying its antecedent
	Teri'i.
	Xârâcùù (Moyse-Faurie 1995:218)
	11.	Kasööjii citââ mwîî kwétaa êêSucker-Bird stand up and 3SG suck up big nä rè jii wave NMLZ-push POSS chief Uvea
		'Sucker-Bird stands up and sucks up the big wave pushed by the chief of Uvea.' (lit.
		'the big wave [which is] the pushing result of the Uvean chief)
	12.	Xûûchî wâ tecâ	cè kètè pôô ù
				Nominalizations are found as the predicates of nominal clauses, i.e.
	without any predicative marker, as in the independent clause Xârâcùù (7) and the equative
	ones in (8) and (9), or in clauses introduced by the predicative marker ko, as in East Uvean
	(10). Most of the following examples include a temporal specification, and are thus anchored
	in time.
	Xârâcùù (Moyse-Faurie 1995:57)
	7.	Kèè-söömè na	rè	panèè-rè		niè.
		NMLZ-kill	PST	POSS father-POSS.3SG he(INDEP)
		'His father killed him.' (Lit. the murder of his father, he)
	8.	Ù-kaxê röö,	kèè-da-xëtë röö.
		NMLZ-big POSS+2SG	NMLZ-eat-hard	POSS+2SG
		'Your size is due to your greediness'.
	9.	Xwâ-sô rè pwâ-mêdè		ngê	xwâda a,	kèè-fädë na rè	xwâchêê...
		NMLZ-fall POSS fruit-orange.tree during year	DEIC NMLZ-walk PST	POSS butterfly
		'The fall of the mandarines from the tree this year is due to the arrival of
		butterflies…'
	East Uvean
	10.	Ko	te	mole kei tō	o	te	kava e	ia.
		PRED	SPEC NEG	PROG plant POSS SPEC kava	ERG	3SG
		'(It is a fact) he doesn't grow kava anymore.'

-sugwétuu rè pabéé-rè.

		child	PFV go.towards for place hole NMLZ-stick	POSS COLL.brother-POSS3SG
		'The child went toward the hole where his brothers were stuck.'
	Tahitian (Lazard & Peltzer 2000:83)
	13.	Teie te	hōho'a o	Teri'i '

o tē haere mai 'araua'e.

  Listen to the noise Dad is making in the forest!' On the other hand, there seem to be specific constraints on nominalizations in this use. In East Uvean, for example, only temporal adverbs, rather than adverbs of other semantic types (such as fa'a 'often' in the East Uvean example below) seem to be possible in such nominalized imperative clauses to express aspect/tense specifications:

	18.	Kwiè xwi	cè	kèè-xwa.
		rain make for	NMLZ-fall
		'It is going to rain soon.' (Lit. rain is preparing for falling)
	19.	Nâ nââbu môrô na	kèè-sa rè	bwè.
		1SG begin already PST	NMLZ -catch
	Xârâcùù
	20.	Cokwa kèè-sa rè	xötö mûduè-rö!
		finish	NMLZ-hit POSS male young.sibling-POSS2SG
		'Stop beating your brother!'
	21.	Xwata kèè-sööté	rè	apaa tö nuö!
		listen	NMLZ-make.noise POSS Dad	in forest
	DEIC ART 'Here is a photo of Teri'i who will come here in a moment.' image POSS Teri'i PRED ART+IPFV go DIR 'East Uvean	soon
	22.	'Aua te	fa'a lau mai o	te	me'a nei !
	(iii) Arguments: Unsurprisingly, nominalizations may occur in verbal clauses, as subjects in PROH SPÉC often say DIR POSS SPEC thing this
	Xârâcùù (14) and as objects in Tahitian (15):
	Xârâcùù (Moyse-Faurie 1995:190)
	14.	Xêê-da rè	nâ xwi, pââ-nâ	wâ siè paii.
		NMLZ-eat POSS 1SG exist tooth-1SG	PFV	NEG ill
		'I can eat, my teeth are not hurting anymore.' (Lit. my possibility of eating exists…)
	Tahitian (Vernaudon et Rigo 2004:467)
	15.	Nāhea te		tatara	i	te	reira	mau fifi?
		how	SPEC	resolve	OBJ	SPEC ANAPH	PL	problem
		'How to resolve these problems?'
	(iv) Causal adjuncts: Nominalizations are also found as causal adjuncts.
	Xârâcùù
	16.	È	xwêê na	xwirè kèè-pûxûrû.
		3SG fall	PST	because NMLZ-run
		'He fell because he was running.'
	East Futunan (Moyse-Faurie 1997:117)
	17.	Kua fifigo lua le	toe i	le	fia	inu.
		PFV	dry	very SPEC	child OBL SPEC DESID drink
		'The child got very thirsty.' (Lit. the child became very dry in the wanting to drink)
	(v) Completives: Nominalizations can occur as clausal complements.
	Xârâcùù

POSS crab 'I had already begun to fish for crabs.' (vi) Imperative clauses: They are also frequent in imperative clauses, as clausal arguments. Don't always tell me this thing! (vii) Exclamative clauses: Finally, nominalizations are used as exclamatives, either as part of larger constructions or as independent utterances. Even though some exclamative constructions are subordinate structures (cf. below examples (29) to (31) of type 3), most of them exhibit specific features, at least in Oceanic languages, which have nothing to do with declaratives or interrogatives, as is typically the case in European languages, but clearly typical properties of nominalization. The use of nominalizations in what is now often called a stance function

  Lit. the goodness of the breadfruit when[one] has fried [it] Similar cases can be found in Xârâcùù (26) and in Cèmuhî (27), where exclamative clauses may also consist of a nominalized verb + a possessive adjunct, most often expressing surprise or admiration. The third type of nominal exclamatives consists of a prepositional phrase with a nominalized head-noun, i.e. a type of subordinate structure. Prepositional exclamative clauses are introduced in East Futunan by the dynamic centrifugal locative preposition ki (PPn *ki) and by the static one (i) in East Uvean.

			galii-ga	o	te	mei	maafai e	falai!
		SPEC good-NMLZ POSS SPEC breadfruit when	NPAST fry
		'Breadfruit is so good when fried!'
	(Xârâcùù
	26.	Kèè-téé	na	rèè!
		NMLZ-look at PST
	27.	A	bwö-bwöli è-ng!
		ART	NMLZ-late	POSS-3SG
	28.	E	fia	ano ki		Lokā ka ko le	mama'o fua!
		NPAST DESID go	OBL	Loka but	PRED SPEC	far
	East Futunan (Moyse-Faurie 1997:181)
	29.	Ki le	fia	sā		o	Paulo 'aia!
		OBL	SPEC DESID show POSS Paulo DEIC
		'How Paulo is boasting!'
	East Uvean
	30.	I	matakovi te	puaká!
		OBL	ugly		SPEC pig
		'How ugly this pig is!'
	In (30), the argument is just placed after the stative verb, but in (31), it is expressed as a
	possessor, maybe because of the presence of an adverb.
	East Uvean
	31.	I	ma'uli lelei o		te	fusi	nei!

POSS+3SG 'How he was looking!' (Lit. his way of having looked at!) Cèmuhî (Mainland of New Caledonia) (Pascale Poiba, p.c.) '[It's incredible] how late he arrives!' The second type of exclamative nominalized clauses is the 'copular-type' nominal clause, i.e. a nominal clause introduced by a predicative marker. East Futunan (Moyse-Faurie 1997:20) INT 'I would like to go to Loka, but it is so far!' OBL life well POSS SPEC banana-tree DEIC

  Other verbal properties are retained to varying degrees. A nominalized transitive clause retains its object argument, encoded in the same manner as in a verbal clause" (2011:192). A similar observation is made byMosel & Hovdhaugen (1992:531) for Samoan: "Nominalized verbal clauses… can be marked for case by prepositions and are determined by articles, but lack TAM particles".

								corresponding
	subordinate clauses (32b) do:
	Tuvaluan (Besnier, 2000:62)
	32a.	Koo oti	te	solooga	o	temotou	fekei.
		PFV	finish SPEC grate+NMLZ POSS 1PL.EXCL	pudding
		'We're done grating the swamp taro [for making] pudding.' (Lit. is finished the
		grating of our swamp taro for pudding)
	32b.	Koo oti	ne	solo temotou fekei.
		PFV	finish PST	grate	1PL.EXCL	pudding

Niko Besnier (2000:510)

made analogous observations for Tuvaluan: "Nominalized verbs come in two types […]: a 'bare' form, which is identical to that of the finite form of the verb; and a suffixed form, which is derived by attaching the nominalizing suffix -Vga to the verb. In both cases, the verb loses its tense-aspect-mood markers". In other words, nominalized clauses cannot occur with tense-aspect-mood markers (32a), whereas the

  SPEC PST see-NMLZ PAUC brother nearly reach SPEC come SPEC mother LOC top

	Te i ite-tina na tunane tata eka te	tihe te	kui	i	una],
	atahi kokoti na	tunane te	ouoho no Hina.
	then cut	PAUC	brothers SPEC hair	POSS Hina

  be.like PRED SPEC give POSS ART salt BEN SPEC IPFV look.for salt DIR '…as, for instance, giving some salt to someone who is looking for salt…' (Lit. it is like the giving of some salt to the one looking for salt…) These constructions are indeed quite frequent in conversational speeches, as is also the case in the following Xârâcùù example.

						:644)
	44.	…e pei o	le	ave o	sina masima ma le	e	sue	masima mai
	Xârâcùù
	45.	Kèè-nä-xwi	rè	wîrî mwâ mê kèè-nä-néxä	rè	wîrî kèè-xwi	rè
	East Futunan
	46.	E	'ita	a Soane i le	koi nonofo a	Malia mo lona tinana.
										still
		staying of Malia and her mother)
	The past progressive marker is also possible in Xârâcùù, as shown below:
	Xârâcùù
	47.	Mââîtaa kèè-nää-fè-cha	rè	ri,	ri	nää	tî	rè	mwâ.
		before	NMLZ-PROG.PST-go-cut POSS 3PL 3PL PROG.PST measure IPFV house
		'Before their going to cut the wood, they were measuring the house.'
	48.	ù-nää-kwé rè		ri
		NMLZ-PROG.PST-dance POSS	3PL
		'the place where they were dancing'
	f) Immediate
	The immediate aspect occurs in nominalizations at least in East Uvean:
	East Uvean
	49.	'E	au nofo pē anai i henī o a'u ki te	hoki liliu mai a	koulua.

NPST NMLZ-IPFV-make POSS 2PL house and NMLZ-IPFV-know POSS 2PL NMLZ-make POSS mwâ mè nä xùpuurè mè wîrî nä bwèrè dèèri rè ngê chaa daa töxû tèpe! house FUT IPFV origin that 2PL IPFV some people IPFV during one day on custom 'The construction of houses, to know how to build houses, will make you men of custom!' e) Progressive The progressive aspect occurs inter alia in East Uvean and in East Futunan nominalizations: IPFV be.angry ABS Soane OBL SPEC PROG RED..stay POSS Malia and her mother 'Soane is angry because Malia is still with her mother.'(Lit. Soane is angry at the NPST 1SG stay RESTR FUT OBL ici up.to SPEC IMM return DIR POSS 2DU

  vote ABS 3SG OBL Petelo OBL NSPEC.PL work lie PST promise

	63.	Na vote a ia kiā Petelo i ni	ga'oi loi na fakapapau kiate ia.
		'e mole ina kai te	mo'i pane i	hana	fia	kai
		PST	NEG 3SG eat SPEC CLAS bread OBL NSPEC+POSS feel.like eat
		kae ne'e ina kai i	te	lahi o	te	me'akai.
		but	PST	3SG eat OBL SPEC big	POSS SPEC food
		'He didn't eat the piece of bread because he was hungry, he ate it because there were
		plenty to eat!' (*i hana kua fia kai)
	East Futunan

PST OBL 3SG

  In nominalized transitive constructions, arguments referring to agents remain in the ergative case, but there is no absolutive case marking in nominalized phrases or clauses, the original absolutive argument (referring to the patient) being marked as an inalienable possessor:

	East Uvean
	79.	'E	sio'i	e	Malia te	kai o	te	mo'i mei	e	Sosefo.
		NPST look.at	ERG	Malia	SPEC eat	POSS SPEC CLF	breadfruit ERG Sosefo
		'Malia is looking at Sosefo eating a piece of breadfruit.' (Lit. Malia is looking at the
		eating of a piece of breadfruit by Sosefo)
							if it refers to a patient (78b):
	East Uvean
	78a.	Pea faifai te	tau		tu'u a	Vaka'ana ki	te	fono.
		and go.on SPÉC often		stand POSS Vaka'ana	OBL	SPÉC	council
		'Vaka'ana was still often going to the council.'
	78b.	Pea ne'e ko te	tu'u 'āfea mai o	te	kolo 'aenī.
		and PST PRED SPEC stand once	DIR.	POSS SPEC	village DEIC
		'And once it was the custom of this village''

  table:

		more verbal features	more nominal features
	tense-aspect	±	±
	specific	±	±
	article
	non-specific	-	+
	prefix	±	±
	affix
	suffix	-	+
	agent as possessor	-	+

I would like to thank an anonymous reviewer, and Ekkehard König, for critical comments and stylistic improvements.

My own data mostly concern several Kanak (New Caledonia: Xârâcùù and Xârâgurè) and Polynesian (East Futunan and East Uvean) languages, on which I have done intensive fieldwork.

Sentential type: all the arguments in Action Nominal Constructions retain their sentential dependingmarking. (id.:61).

 6 In other Austronesian but non-Oceanic languages, negative markers may also be part of nominalized constructions:Kaufman (2011:743) gives Tagalog examples with what he calls "gerunds", that is, our action nominalizations, which include a negative marker:ang hindi mo pag-pasok NOM NEG 2SG.POSS GER-enter 'your not entering'

Directionals can occur with verbs and in nominalizations, but not with 'true' nouns (p. 439).

There is, however, an exception: when the transitive verb is nominalized by a suffix ( § 3.2.2.), the patient cannot be expressed as a possessive phrase; it remains unmarked, as it is the case in an accusative language such as Xârâcùù.

This evolution is attested elsewhere in the world, as for example in Tibeto-Burman languages or in Mandarin dialects. In a recent communication,[START_REF] Coupe | Communication on "Polyfunctional nominalizations in Tibeto-Birman: trajectories of grammaticalization[END_REF] addressed the following question: "Is it mere coincidence that two nominalizers are isomorphic with two of the tense markers of Mongsen Ao, or do nominalizers provide a diachronic source for yet another extended function of nominalization in this language, namely the tense/mood categories?"[START_REF] Coupe | Communication on "Polyfunctional nominalizations in Tibeto-Birman: trajectories of grammaticalization[END_REF]).

Abbreviations