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Talk:Copenhagen interpretation

Teller Copenhagen interpretation
Anybody have scholarly sources for Edward Teller's Copenhagen interpretation? I find it very convincing but I'd prefer a formal treatment instead of the colloquial explanation he gives on Web of Stories:

"With one special remark; if you make a measurement which defines the position precisely, this measurement does not require an observer. Indeed, it is entirely independent. Something might happen a billion years ago and I can find in the geological remains that this or that has happened, no observer. What happens in a measurement is what is called - excuse me for introducing a new concept, which I will explain - something must happen which is called an Irreversible Process. And I will show you an irreversible process right here. Here is this hopefully empty cup and I drop it. Now, what happens in physics forward can also happen backward. The equations are so constructed that everything that happens one way can happen also the opposite way. So therefore, having stopped this- dropped this cup, I stand here with my hand open and wait for the cup to rise again, not as I do it, lifting it, but of its own accord, redoing the whole thing and landing in my hand. You all know that if that can happen at all you have to have a lot of patience, a patience greatly exceeding the age of the universe which is about as good as saying it never can happen. And the interference phenomenon, a peculiar thing in quantum mechanics, will show up its consequences in whatever else I do with this object. Because from the end state, I can reconstruct the initial state, except if there is an irreversible process. A measurement is not defined by Eugene Wigner knowing about it, or anybody else, it is defined by an irreversible process which does not allow the original state to be reconstructed from the final state. It is in this sense that Heisenberg should be understood. And he's talking of it- about an observer. It's simply justified as a didactic device, as a device to explain things, so people understand more easily what an observer is than to say what an irreversible process is."

It appears Teller eliminates the observer and the wavefunction collapse out of the Copenhagen interpretation and replaces them with a statistically "irreversible" wavefunction, which doesn't appear to be formally irreversible, just that it has a near zero probability. HueSurname (talk) 16:47, 1 January 2021 (UTC)

 * He is describing the process we now call decoherence, that a "measurement" in quantum mechanics which converts a superposition into a unique classical state, which is described in the Copenhagen interpretation as "wavefunction collapse", may actually occur by a thermodynamically irreversible process, like the dropped coffee cup. All "measurements" or "observations" in quantum mechanics are irreversible processes, which is what causes apparent wavefunction collapse.  For example, in the Schrodinger's cat experiment, the detection of the atomic particle by the geiger counter, and the amplification of the signal by the electronics to actuate the release of the poison, are irreversible processes.  It is this irreversible entanglement of the quantum superposition with the wavefunction of a large number of particles, the "external world", that causes the different components ("eigenstates") of the superposition ("live cat" and "dead cat" in Schro's experiment) to become mutually unobservable, so it appears that only one of the possibilities has occurred.

 * This process wasn't really recognised in the Copenhagen Interpretation, the wavefunction of the external world wasn't considered. In the CI, the world is divided into the "experiment", which is described quantum mechanically, and the "observer", "measuring apparatus" or "external world", which is described classically.  As you say, in this 1998 speech Teller replaces the outside world by its wavefunction, but this wasn't his own idea.  The effect of the entanglement of the apparatus wavefunction with the world's wavefunction had been discovered Heinz-Dieter Zeh in the 1970s.   The fact that the irreversibility of the measuring apparatus increased the state space occupied by the entangled wavefunction, causing decoherence which resulted in only one eigenstate being observable, was first published in a 1970 paper by Zeh. This isn't part of the Copenhagen Interpretation, or any interpretation.  --ChetvornoTALK 00:23, 11 April 2021 (UTC)

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The miscellaneous quotations added in this edit do not, in my view, contribute clarity to the article. We already summarize the serious scholarship by Howard and others that indicates how ahistorical invocations of "the" Copenhagen interpretation are. Questioning the unity of "the" Copenhagen interpretation is at least as old as Jammer's book in 1974, or in other words, only about twenty years younger than the use of "Copenhagen interpretation" in print. The lengthy quotation from Beller is orthogonal to the question of how the term originated, and the others are repetitive, seemingly chosen at random, and do not convey additional information. (An offhand mention in a book about falling cats? It's a fine book — I've read it — but really?) The lengthy quotation from Stone is mostly tangential as well, and pushes a POV that plenty of physicists have disagreed with, from Heisenberg on; I mean, how easy is it to visualize a wave function for more than one particle? For a finite-dimensional Hilbert space bigger than a single qubit? And while the term "wave mechanics" might be mostly used these days to talk about the history of quantum physics, it didn't vanish entirely; it's still in use, being roughly synonymous with "Schrödinger picture". XOR'easter (talk) 20:15, 25 November 2021 (UTC)

Lead vs Body on the origin and meaning of topic.
As the section on Origin points out, the "Copenhagen interpretation" is not a characterization espoused by any of the principals listed in the lead paragraph. An encyclopedic approach to the topic should start with what "it" is and "it" is a name coined in the mid-1950s for ideas partly traceable to Bohr and Heisenberg, but also Born Dirac and von Neumann, and many others. In fact the breadth contributors to the "Copenhagen interpretation" is exactly why it is the most commonly taught. Johnjbarton (talk) 22:30, 10 August 2023 (UTC)

 * I've tried adjusting the intro. Faye's article in the Stanford Encyclopedia of Philosophy lists Born right up there with Bohr and Heisenberg; Dirac and maybe Pauli could potentially be mentioned too. XOR'easter (talk) 22:32, 11 August 2023 (UTC)
 * Thanks Johnjbarton (talk) 00:24, 12 August 2023 (UTC)

The Heisenberg cut
I renamed a section to The Heisenberg cut. This section is confusing. It mixes up quantum discontinuity, measurement, and quantum system definition, plus some goop about observers and cosmology, with a dollop of mind projection fallacy. Johnjbarton (talk) 00:27, 12 August 2023 (UTC)

 * We can probably tidy it up and maybe move some stuff around, but I'm not sure what's intrinsically confusing about it. There's a cluster of related complaints about the Copenhagen interpretation(s), sometimes phrased as having to make a division between quantum and classical, or between microscopic and macroscopic, reversible and irreversible, etc. Quantum cosmology is then claimed to be a setting where the Copenhagen interpretation(s) can't work, because there is no "outside". XOR'easter (talk) 00:40, 12 August 2023 (UTC)

title: Talk:Copenhagen interpretation


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Cornish language

Cornish (Standard Written Form: Kernewek or Kernowek; ) is a Southwestern Brittonic language of the Celtic language family. Along with Welsh and Breton, Cornish is descended from the Common Brittonic language spoken throughout much of Great Britain before the English language came to dominate. For centuries, until it was pushed westwards by English, it was the main language of Cornwall, maintaining close links with its sister language Breton, with which it was mutually intelligible, perhaps even as long as Cornish continued to be spoken as a vernacular. Cornish continued to function as a common community language in parts of Cornwall until the mid 18th century, and there is some evidence for traditional speakers of the language persisting into the 19th century.

Cornish became extinct as a living community language in Cornwall by the end of the 18th century, although knowledge of Cornish, including speaking ability to a certain extent, persisted within some families and individuals. A revival started in the early 20th century, and in 2010 UNESCO reclassified the language as critically endangered, stating that its former classification of the language as extinct was no longer accurate. The language has a growing number of second-language speakers, and a very small number of families now raise children to speak revived Cornish as a first language.

Cornish is currently recognised under the European Charter for Regional or Minority Languages, and the language is often described as an important part of Cornish identity, culture and heritage. Since the revival of the language, some Cornish textbooks and works of literature have been published, and an increasing number of people are studying the language. Recent developments include Cornish music, independent films, and children's books. A small number of people in Cornwall have been brought up to be bilingual native speakers, and the language is taught in schools and appears on street nameplates. The first Cornish-language day care opened in 2010.

Classification
Cornish is a Southwestern Brittonic language, a branch of the Insular Celtic section of the Celtic language family, which is a sub-family of the Indo-European language family. Brittonic also includes Welsh, Breton, Cumbric and possibly Pictish, the last two of which are extinct. Scottish Gaelic, Irish and Manx are part of the separate Goidelic branch of Insular Celtic.

Joseph Loth viewed Cornish and Breton as being two dialects of the same language, claiming that "Middle Cornish is without doubt closer to Breton as a whole than the modern Breton dialect of Quiberon [Kiberen] is to that of Saint-Pol-de-Léon [Kastell-Paol]." Also, Kenneth Jackson argued that it is almost certain that Cornish and Breton would have been mutually intelligible as long as Cornish was a living language, and that Cornish and Breton are especially closely related to each other and less closely related to Welsh.

History

Cornish evolved from the Common Brittonic spoken throughout Britain south of the Firth of Forth during the British Iron Age and Roman period. As a result of westward Anglo-Saxon expansion, the Britons of the southwest were separated from those in modern-day Wales and Cumbria, which Jackson links to the defeat of the Britons at the Battle of Deorham in about 577. The western dialects eventually evolved into modern Welsh and the now extinct Cumbric, while Southwestern Brittonic developed into Cornish and Breton, the latter as a result of emigration to parts of the continent, known as Brittany over the following centuries.

Old Cornish
The area controlled by the southwestern Britons was progressively reduced by the expansion of Wessex over the next few centuries. During the Old Cornish (Kernewek Koth) period (800–1200), the Cornish-speaking area was largely coterminous with modern-day Cornwall, after the Saxons had taken over Devon in their south-westward advance, which probably was facilitated by a second migration wave to Brittany that resulted in the partial depopulation of Devon.

The earliest written record of the Cornish language comes from this period: a 9th-century gloss in a Latin manuscript of De Consolatione Philosophiae by Boethius, which used the words ud rocashaas. The phrase may mean "it [the mind] hated the gloomy places", or alternatively, as Andrew Breeze suggests, "she hated the land". Other sources from this period include the Saints' List, a list of almost fifty Cornish saints, the Bodmin manumissions, which is a list of manumittors and slaves, the latter with mostly Cornish names, and, more substantially, a Latin-Cornish glossary (the Vocabularium Cornicum or Cottonian Vocabulary), a Cornish translation of Ælfric of Eynsham's Latin-Old English Glossary, which is thematically arranged into several groups, such as the Genesis creation narrative, anatomy, church hierarchy, the family, names for various kinds of artisans and their tools, flora, fauna, and household items. The manuscript was widely thought to be in Old Welsh until the 18th century when it was identified as Cornish by Edward Lhuyd. Some Brittonic glosses in the 9th-century colloquy De raris fabulis were once identified as Old Cornish, but they are more likely Old Welsh, possibly influenced by a Cornish scribe. No single phonological feature distinguishes Cornish from both Welsh and Breton until the beginning of the assibilation of dental stops in Cornish, which is not found before the second half of the eleventh century, and it is not always possible to distinguish Old Cornish, Old Breton, and Old Welsh orthographically.

Middle Cornish
The Cornish language continued to flourish well through the Middle Cornish (Kernewek Kres) period (1200–1600), reaching a peak of about 39,000 speakers in the 13th century, after which the number started to decline. This period provided the bulk of traditional Cornish literature, and was used to reconstruct the language during its revival. Most important is the Ordinalia, a cycle of three mystery plays, Origo Mundi, Passio Christi and Resurrexio Domini. Together these provide about 8,734 lines of text. The three plays exhibit a mixture of English and Brittonic influences, and, like other Cornish literature, may have been written at Glasney College near Penryn. From this period also are the hagiographical dramas Beunans Meriasek (The Life of Meriasek) and Bewnans Ke (The Life of Ke), both of which feature as an antagonist the villainous and tyrannical King Tewdar (or Teudar), a historical medieval king in Armorica and Cornwall, who, in these plays, has been interpreted as a lampoon of either of the Tudor kings Henry VII or Henry VIII.

Others are the Charter Fragment, the earliest known continuous text in the Cornish language, apparently part of a play about a medieval marriage, and Pascon agan Arluth (The Passion of Our Lord), a poem probably intended for personal worship, were written during this period, probably in the second half of the 14th century. Another important text, the Tregear Homilies, was realized to be Cornish in 1949, having previously been incorrectly classified as Welsh. It is the longest text in the traditional Cornish language, consisting of around 30,000 words of continuous prose. This text is a late 16th century translation of twelve of Bishop Bonner's thirteen homilies by a certain John Tregear, tentatively identified as a vicar of St Allen from Crowan, and has an additional catena, Sacrament an Alter, added later by his fellow priest, Thomas Stephyn. In the reign of Henry VIII, an account was given by Andrew Boorde in his 1542 Boke of the Introduction of Knowledge. He states, "In Cornwall is two speches, the one is naughty Englysshe, and the other is Cornysshe speche. And there be many men and women the which cannot speake one worde of Englysshe, but all Cornyshe."

When Parliament passed the Act of Uniformity 1549, which established the 1549 edition of the English Book of Common Prayer as the sole legal form of worship in England, including Cornwall, people in many areas of Cornwall did not speak or understand English. The passing of this Act was one of the causes of the Prayer Book Rebellion (which may also have been influenced by government repression after the failed Cornish rebellion of 1497), with "the commoners of Devonshyre and Cornwall" producing a manifesto demanding a return to the old religious services and included an article that concluded, "and so we the Cornyshe men (whereof certen of us understande no Englysh) utterly refuse thys newe Englysh." In response to their articles, the government spokesman (either Philip Nichols or Nicholas Udall) wondered why they did not just ask the king for a version of the liturgy in their own language. Archbishop Thomas Cranmer asked why the Cornishmen should be offended by holding the service in English, when they had before held it in Latin, which even fewer of them could understand. Anthony Fletcher points out that this rebellion was primarily motivated by religious and economic, rather than linguistic, concerns. The rebellion prompted a heavy-handed response from the government, and 5,500 people died during the fighting and the rebellion's aftermath. Government officials then directed troops under the command of Sir Anthony Kingston to carry out pacification operations throughout the West Country. Kingston subsequently ordered the executions of numerous individuals suspected of involvement with the rebellion as part of the post-rebellion reprisals.

The rebellion eventually proved a turning-point for the Cornish language, as the authorities came to associate it with sedition and "backwardness". This proved to be one of the reasons why the Book of Common Prayer was never translated into Cornish (unlike Welsh), as proposals to do so were suppressed in the rebellion's aftermath. The failure to translate the Book of Common Prayer into Cornish led to the language's rapid decline during the 16th and 17th centuries. Peter Berresford Ellis cites the years 1550–1650 as a century of immense damage for the language, and its decline can be traced to this period. In 1680 William Scawen wrote an essay describing 16 reasons for the decline of Cornish, among them the lack of a distinctive Cornish alphabet, the loss of contact between Cornwall and Brittany, the cessation of the miracle plays, loss of records in the Civil War, lack of a Cornish Bible and immigration to Cornwall. Mark Stoyle, however, has argued that the 'glotticide' of the Cornish language was mainly a result of the Cornish gentry adopting English to dissociate themselves from the reputation for disloyalty and rebellion associated with the Cornish language since the 1497 uprising.

Late Cornish
By the middle of the 17th century, the language had retreated to Penwith and Kerrier, and transmission of the language to new generations had almost entirely ceased. In his Survey of Cornwall, published in 1602, Richard Carew writes:"[M]ost of the inhabitants can speak no word of Cornish, but very few are ignorant of the English; and yet some so affect their own, as to a stranger they will not speak it; for if meeting them by chance, you inquire the way, or any such matter, your answer shall be, 'Meea navidna caw zasawzneck,' 'I [will] speak no Saxonage.'" The Late Cornish (Kernewek Diwedhes) period from 1600 to about 1800 has a less substantial body of literature than the Middle Cornish period, but the sources are more varied in nature, including songs, poems about fishing and curing pilchards, and various translations of verses from the Bible, the Ten Commandments, the Lord's Prayer and the Creed. Edward Lhuyd's Archaeologia Britannica, which was mainly recorded in the field from native speakers in the early 1700s, and his unpublished field notebook are seen as important sources of Cornish vocabulary, some of which are not found in any other source. Archaeologia Britannica also features a complete version of a traditional folk tale, John of Chyanhor, a short story about a man from St Levan who goes far to the east seeking work, eventually returning home after three years to find that his wife has borne him a child during his absence.

In 1776, William Bodinar, who describes himself as having learned Cornish from old fishermen when he was a boy, wrote a letter to Daines Barrington in Cornish, with an English translation, which was probably the last prose written in the traditional language. In his letter, he describes the sociolinguistics of the Cornish language at the time, stating that there are no more than four or five old people in his village who can still speak Cornish, concluding with the remark that Cornish is no longer known by young people. However, the last recorded traditional Cornish literature may have been the Cranken Rhyme, a corrupted version of a verse or song published in the late 19th century by John Hobson Matthews, recorded orally by John Davey (or Davy) of Boswednack, of uncertain date but probably originally composed during the last years of the traditional language. Davey had traditional knowledge of at least some Cornish. John Kelynack (1796–1885), a fisherman of Newlyn, was sought by philologists for old Cornish words and technical phrases in the 19th century.

Decline of Cornish speakers between 1300 and 1800

It is difficult to state with certainty when Cornish ceased to be spoken, due to the fact that its last speakers were of relatively low social class and that the definition of what constitutes "a living language" is not clear cut. Peter Pool argues that by 1800 nobody was using Cornish as a daily language and no evidence exists of anyone capable of conversing in the language at that date. However, passive speakers, semi-speakers and rememberers, who retain some competence in the language despite not being fluent nor using the language in daily life, generally survive even longer.

The traditional view that Dolly Pentreath (1692–1777) was the last native speaker of Cornish has been challenged, and in the 18th and 19th centuries there was academic interest in the language and in attempting to find the last speaker of Cornish. It has been suggested that, whereas Pentreath was probably the last monolingual speaker, the last native speaker may have been John Davey of Zennor, who died in 1891. However, although it is clear Davey possessed some traditional knowledge in addition to having read books on Cornish, accounts differ of his competence in the language. Some contemporaries stated he was able to converse on certain topics in Cornish whereas others affirmed they had never heard him claim to be able to do so. Robert Morton Nance, who reworked and translated Davey's Cranken Rhyme, remarked, "There can be no doubt, after the evidence of this rhyme, of what there was to lose by neglecting John Davey."

The search for the last speaker is hampered by a lack of transcriptions or audio recordings, so that it is impossible to tell from this distance whether the language these people were reported to be speaking was Cornish, or English with a heavy Cornish substratum, nor what their level of fluency was. Nevertheless this academic interest, along with the beginning of the Celtic Revival in the late 19th century, provided the groundwork for a Cornish language revival movement.

Notwithstanding the uncertainty over who was the last speaker of Cornish, researchers have posited the following numbers for the prevalence of the language between 1050 and 1800.

Revived Cornish
In 1904, the Celtic language scholar and Cornish cultural activist Henry Jenner published A Handbook of the Cornish Language. The publication of this book is often considered to be the point at which the revival movement started. Jenner wrote about the Cornish language in 1905, "one may fairly say that most of what there was of it has been preserved, and that it has been continuously preserved, for there has never been a time when there were not some Cornishmen who knew some Cornish."

The revival focused on reconstructing and standardising the language, including coining new words for modern concepts, and creating educational material in order to teach Cornish to others. In 1929 Robert Morton Nance published his Unified Cornish (Kernewek Unys) system, based on the Middle Cornish literature while extending the attested vocabulary with neologisms and forms based on Celtic roots also found in Breton and Welsh, publishing a dictionary in 1938. Nance's work became the basis of revived Cornish (Kernewek Dasserghys) for most of the 20th century. During the 1970s, criticism of Nance's system, including the inconsistent orthography and unpredictable correspondence between spelling and pronunciation, as well as on other grounds such as the archaic basis of Unified and a lack of emphasis on the spoken language, resulted in the creation of several rival systems. In the 1980s, Ken George published a new system, Kernewek Kemmyn ('Common Cornish'), based on a reconstruction of the phonological system of Middle Cornish, but with an approximately morphophonemic orthography. It was subsequently adopted by the Cornish Language Board and was the written form used by a reported 54.5% of all Cornish language users according to a survey in 2008, but was heavily criticised for a variety of reasons by Jon Mills and Nicholas Williams, including making phonological distinctions that they state were not made in the traditional language c. 1500, failing to make distinctions that they believe were made in the traditional language at this time, and the use of an orthography that deviated too far from the traditional texts and Unified Cornish. Also during this period, Richard Gendall created his Modern Cornish system (also known as Revived Late Cornish), which used Late Cornish as a basis, and Nicholas Williams published a revised version of Unified;  however neither of these systems gained the popularity of Unified or Kemmyn.

The revival entered a period of factionalism and public disputes, with each orthography attempting to push the others aside. By the time that Cornish was recognised by the UK government under the European Charter for Regional or Minority Languages in 2002, it had become recognised that the existence of multiple orthographies was unsustainable with regards to using the language in education and public life, as none had achieved a wide consensus. A process of unification was set about which resulted in the creation of the public-body Cornish Language Partnership in 2005 and agreement on a Standard Written Form in 2008. In 2010 a new milestone was reached when UNESCO altered its classification of Cornish, stating that its previous label of "extinct" was no longer accurate.

Geographic distribution and number of speakers
Speakers of Cornish reside primarily in Cornwall, which has a population of 563,600 (2017 estimate). There are also some speakers living outside Cornwall, particularly in the countries of the Cornish diaspora, as well as in other Celtic nations. Estimates of the number of Cornish speakers vary according to the definition of a speaker, and is difficult to determine accurately due to the individualised nature of language take-up. Nevertheless, there is recognition that the number of Cornish speakers is growing. From before the 1980s to the end of the 20th century there was a sixfold increase in the number of speakers to around 300. One figure for the number of people who know a few basic words, such as knowing that "Kernow" means "Cornwall", was 300,000; the same survey gave the number of people able to have simple conversations as 3,000.

The Cornish Language Strategy project commissioned research to provide quantitative and qualitative evidence for the number of Cornish speakers: due to the success of the revival project it was estimated that 2,000 people were fluent (surveyed in spring 2008), an increase from the estimated 300 people who spoke Cornish fluently suggested in a study by Kenneth MacKinnon in 2000.

Jenefer Lowe of the Cornish Language Partnership said in an interview with the BBC in 2010 that there were around 300 fluent speakers. Bert Biscoe, a councillor and bard, in a statement to the Western Morning News in 2014 said there were "several hundred fluent speakers". Cornwall Council estimated in 2015 that there were 300–400 fluent speakers who used the language regularly, with 5,000 people having a basic conversational ability in the language.

A report on the 2011 Census published in 2013 by the Office for National Statistics placed the number of speakers at somewhere between 325 and 625. In 2017 the ONS released data based on the 2011 Census that placed the number of speakers at 557 people in England and Wales who declared Cornish to be their main language, 464 of whom lived in Cornwall. The 2021 census listed the number of Cornish speakers at 563.

A study that appeared in 2018 established the number of people in Cornwall with at least minimal skills in Cornish, such as the use of some words and phrases, to be more than 3,000, including around 500 estimated to be fluent.

The Institute of Cornish Studies at the University of Exeter is working with the Cornish Language Partnership to study the Cornish language revival of the 20th century, including the growth in number of speakers.

Legal status and recognition

In 2002, Cornish was recognized by the UK government under Part II of the European Charter for Regional or Minority Languages. UNESCO's Atlas of World Languages classifies Cornish as "critically endangered". UNESCO has said that a previous classification of 'extinct' "does not reflect the current situation for Cornish" and is "no longer accurate".

Within the UK
Cornwall Council's policy is to support the language, in line with the European Charter. A motion was passed in November 2009 in which the council promoted the inclusion of Cornish, as appropriate and where possible, in council publications and on signs. This plan has drawn some criticism. In October 2015, The council announced that staff would be encouraged to use "basic words and phrases" in Cornish when dealing with the public. In 2021 Cornwall Council prohibited a marriage ceremony from being conducted in Cornish as the Marriage Act 1949 only allowed for marriage ceremonies in English or Welsh.

In 2014, the Cornish people were recognised by the UK Government as a national minority under the Framework Convention for the Protection of National Minorities. The FCNM provides certain rights and protections to a national minority with regard to their minority language.

In 2016, British government funding for the Cornish language ceased, and responsibility transferred to Cornwall Council.

Old Cornish orthography
Until around the middle of the 11th century, Old Cornish scribes used a traditional spelling system shared with Old Breton and Old Welsh, based on the pronunciation of British Latin. By the time of the Vocabularium Cornicum, usually dated to around 1100, Old English spelling conventions, such as the use of thorn (Þ, þ) and eth (Ð, ð) for dental fricatives, and wynn (Ƿ, ƿ) for /w/, had come into use, allowing documents written at this time to be distinguished from Old Welsh, which rarely uses these characters, and Old Breton, which does not use them at all. Old Cornish features include using initial ⟨ch⟩, ⟨c⟩, or ⟨k⟩ for /k/, and, in internal and final position, ⟨p⟩, ⟨t⟩, ⟨c⟩, ⟨b⟩, ⟨d⟩, and ⟨g⟩ are generally used for the phonemes /b/, /d/, /ɡ/, /β/, /ð/, and /ɣ/ respectively, meaning that the results of Brittonic lenition are not usually apparent from the orthography at this time.

Middle Cornish orthography
Middle Cornish orthography has a significant level of variation, and shows influence from Middle English spelling practices. Yogh (Ȝ ȝ) is used in certain Middle Cornish texts, where it is used to represent a variety of sounds, including the dental fricatives /θ/ and /ð/, a usage which is unique to Middle Cornish and is never found in Middle English. Middle Cornish scribes tend to use ⟨c⟩ for /k/ before back vowels, and ⟨k⟩ for /k/ before front vowels, though this is not always true, and this rule is less consistent in certain texts. Middle Cornish scribes almost universally use ⟨wh⟩ to represent /ʍ/ (or /hw/), as in Middle English. Middle Cornish, especially towards the end of this period, tends to use orthographic ⟨g⟩ and ⟨b⟩ in word-final position in stressed monosyllables, and ⟨k⟩ and ⟨p⟩ in word-final position in unstressed final syllables, to represent the reflexes of late Brittonic /ɡ/ and /b/, respectively.

Late Cornish orthography
Written sources from this period are often spelled following English spelling conventions since many of the writers of the time had not been exposed to Middle Cornish texts or the Cornish orthography within them. Around 1700, Edward Lhuyd visited Cornwall, introducing his own partly phonetic orthography that he used in his Archaeologia Britannica, which was adopted by some local writers, leading to the use of some Lhuydian features such as the use of circumflexes to denote long vowels, ⟨k⟩ before front vowels, word-final ⟨i⟩, and the use of ⟨dh⟩ to represent the voiced dental fricative /ð/.

Revived Cornish orthography
After the publication of Jenner's Handbook of the Cornish Language, the earliest revivalists used Jenner's orthography, which was influenced by Lhuyd's system. This system was abandoned following the development by Nance of a "unified spelling", later known as Unified Cornish, a system based on a standardization of the orthography of the early Middle Cornish texts. Nance's system was used by almost all Revived Cornish speakers and writers until the 1970s. Criticism of Nance's system, particularly the relationship of spelling to sounds and the phonological basis of Unified Cornish, resulted in rival orthographies appearing by the early 1980s, including Gendal's Modern Cornish, based on Late Cornish native writers and Lhuyd, and Ken George's Kernewek Kemmyn, a mainly morphophonemic orthography based on George's reconstruction of Middle Cornish c. 1500, which features a number of orthographic, and phonological, distinctions not found in Unified Cornish. Kernewek Kemmyn is characterised by the use of universal ⟨k⟩ for /k/ (instead of ⟨c⟩ before back vowels as in Unified); ⟨hw⟩ for /hw/, instead of ⟨wh⟩ as in Unified; and ⟨y⟩, ⟨oe⟩, and ⟨eu⟩ to represent the phonemes /ɪ/, /o/, and /œ/ respectively, which are not found in Unified Cornish. Criticism of all of these systems, especially Kernewek Kemmyn, by Nicolas Williams, resulted in the creation of Unified Cornish Revised, a modified version of Nance's orthography, featuring: an additional phoneme not distinguished by Nance, "ö in German schön", represented in the UCR orthography by ⟨ue⟩; replacement of ⟨y⟩ with ⟨e⟩ in many words; internal ⟨h⟩ rather than ⟨gh⟩; and use of final ⟨b⟩, ⟨g⟩, and ⟨dh⟩ in stressed monosyllables. A Standard Written Form, intended as a compromise orthography for official and educational purposes, was introduced in 2008, although a number of previous orthographic systems remain in use and, in response to the publication of the SWF, another new orthography, Kernowek Standard, was created, mainly by Nicholas Williams and Michael Everson, which is proposed as an amended version of the Standard Written Form.

Phonology
The phonological system of Old Cornish, inherited from Proto-Southwestern Brittonic and originally differing little from Old Breton and Old Welsh, underwent various changes during its Middle and Late phases, eventually resulting in several characteristics not found in the other Brittonic languages. The first sound change to distinguish Cornish from both Breton and Welsh, the assibilation of the dental stops and  in medial and final position, had begun by the time of the Vocabularium Cornicum, c. 1100 or earlier. This change, and the subsequent, or perhaps dialectical, palatalization (or occasional rhotacization in a few words) of these sounds, results in orthographic forms such as Middle Cornish tas 'father', Late Cornish tâz (Welsh tad), Middle Cornish cresy 'believe', Late Cornish cregy (Welsh credu), and Middle Cornish gasa 'leave', Late Cornish gara (Welsh gadael). A further characteristic sound change, pre-occlusion, occurred during the 16th century, resulting in the nasals and  being realised as  and  respectively in stressed syllables, and giving Late Cornish forms such as pedn 'head' (Welsh pen) and kabm 'crooked' (Welsh cam).

As a revitalised language, the phonology of contemporary spoken Cornish is based on a number of sources, including various reconstructions of the sound system of middle and early modern Cornish based on an analysis of internal evidence such as the orthography and rhyme used in the historical texts, comparison with the other Brittonic languages Breton and Welsh,  and the work of the linguist Edward Lhuyd, who visited Cornwall in 1700 and recorded the language in a partly phonetic orthography.

Vocabulary
Cornish is a Celtic language, and the majority of its vocabulary, when usage frequency is taken into account, at every documented stage of its history is inherited direct from Proto-Celtic, either through the ancestral Proto-Indo-European language, or through vocabulary borrowed from unknown substrate language(s) at some point in the development of the Celtic proto-language from PIE. Examples of the PIE > PCelt. development are various terms related to kinship and people, including mam 'mother', modereb 'aunt, mother's sister', huir 'sister', mab 'son', gur 'man', den 'person, human', and tus 'people', and words for parts of the body, including lof 'hand' and dans 'tooth'. Inherited adjectives with an Indo-European etymology include newyth 'new', ledan 'broad, wide', rud 'red', hen 'old', iouenc 'young', and byw 'alive, living'.

Several Celtic or Brittonic words cannot be reconstructed to Proto-Indo-European, and are suggested to have been borrowed from unknown substrate language(s) at an early stage, such as Proto-Celtic or Proto-Brittonic. Proposed examples in Cornish include coruf 'beer' and broch 'badger'.

Other words in Cornish inherited direct from Proto-Celtic include a number of toponyms, for example bre 'hill', din 'fort', and bro 'land', and a variety of animal names such as logoden 'mouse', mols 'wether', mogh 'pigs', and tarow 'bull'.

During the Roman occupation of Britain a large number (around 800) of Latin loan words entered the vocabulary of Common Brittonic, which subsequently developed in a similar way to the inherited lexicon. These include brech 'arm' (from British Latin bracc(h)ium), ruid 'net' (from retia), and cos 'cheese' (from caseus).

A substantial number of loan words from English and to a lesser extent French entered the Cornish language throughout its history. Whereas only 5% of the vocabulary of the Old Cornish Vocabularium Cornicum is thought to be borrowed from English, and only 10% of the lexicon of the early modern Cornish writer William Rowe, around 42% of the vocabulary of the whole Cornish corpus is estimated to be English loan words, without taking frequency into account. (However, when frequency is taken into account, this figure for the entire corpus drops to 8%.) The many English loanwords, some of which were sufficiently well assimilated to acquire native Cornish verbal or plural suffixes or be affected by the mutation system, include redya 'to read', onderstondya 'to understand', ford 'way', hos 'boot' and creft 'art'.

Many Cornish words, such as mining and fishing terms, are specific to the culture of Cornwall. Examples include atal 'mine waste' and beetia 'to mend fishing nets'. Foogan and hogan are different types of pastries. Troyl is a 'traditional Cornish dance get-together' and Furry is a specific kind of ceremonial dance that takes place in Cornwall. Certain Cornish words may have several translation equivalents in English, so for instance lyver may be translated into English as either 'book' or 'volume' and dorn can mean either 'hand' or 'fist'. As in other Celtic languages, Cornish lacks a number of verbs commonly found in other languages, including modals and psych-verbs; examples are 'have', 'like', 'hate', 'prefer', 'must/have to' and 'make/compel to'. These functions are instead fulfilled by periphrastic constructions involving a verb and various prepositional phrases.

Grammar
The grammar of Cornish shares with other Celtic languages a number of features which, while not unique, are unusual in an Indo-European context. The grammatical features most unfamiliar to English speakers of the language are the initial consonant mutations, the verb–subject–object word order, inflected prepositions, fronting of emphasised syntactic elements and the use of two different forms for 'to be'.

Mutations
Cornish has initial consonant mutation: The first sound of a Cornish word may change according to grammatical context. As in Breton, there are four types of mutation in Cornish (compared with three in Welsh, two in Irish and Manx and one in Scottish Gaelic). These changes apply to only certain letters (sounds) in particular grammatical contexts, some of which are given below:

 * Lenition or "soft" mutation:
 * Feminine singular nouns are lenited after an 'the':
 * kath 'cat' > an gath 'the cat'
 * Spirantization or "aspirate" mutation:
 * Nouns are spirantized after ow 'my':
 * tas 'father' > ow thas 'my father'
 * Provection or "hard" mutation:
 * Verbs are provected after the verbal particle ow (approximately English "-ing"):
 * gweles 'see' > ow kweles 'seeing'
 * Lenition followed by provection (usually), or "mixed" mutation:
 * Type 1 mixed mutation:
 * Occurs after the affirmative particle y:
 * gwelav > y hwelav 'I see'
 * Type 2 mixed mutation:
 * Occurs after 2nd person singular infixed pronoun 'th:
 * dorn 'hand' > y'th torn 'in thy hand'

Articles
Cornish has no indefinite article. Porth can either mean 'harbour' or 'a harbour'. In certain contexts, unn can be used, with the meaning 'a certain, a particular', e.g. unn porth 'a certain harbour'. There is, however, a definite article an 'the', which is used for all nouns regardless of their gender or number, e.g. an porth 'the harbour'.

Nouns
Cornish nouns belong to one of two grammatical genders, masculine and feminine, but are not inflected for case. Nouns may be singular or plural. Plurals can be formed in various ways, depending on the noun:

 * Vowel change:
 * toll 'hole' > tell 'holes'
 * Addition of a specific plural suffix:
 * el 'angel' > eledh 'angels'
 * tas 'father' > tasow 'fathers'
 * gwikor 'peddler' > gwikoryon 'peddlers'
 * Suppletion:
 * den 'man' > tus 'men, people'

Some nouns are collective or mass nouns. Singulatives can be formed from collective nouns by the addition of the suffix ⫽-enn⫽ (SWF -en):

 * gwels 'grass' > gwelsen 'a blade of grass'
 * helyk 'willow-trees' > helygen 'a willow tree'

Verbs
Verbs are conjugated for person, number, tense and mood. For example, the verbal noun gweles 'see' has derived forms such as 1st person singular present indicative gwelav 'I see', 3rd person plural imperfect indicative gwelens 'they saw', and 2nd person singular imperative gwel 'see!' Grammatical categories can be indicated either by inflection of the main verb, or by the use of auxiliary verbs such as bos 'be' or gul 'do'.

Prepositions
Cornish uses inflected (or conjugated) prepositions: Prepositions are inflected for person and number. For example, gans (with, by) has derived forms such as genev 'with me', ganso 'with him', and genowgh 'with you (plural)'.

Syntax
Word order in Cornish is somewhat fluid and varies depending on several factors such as the intended element to be emphasised and whether a statement is negative or affirmative. In a study on Cornish word order in the play Bewnans Meriasek (c. 1500), Ken George has argued that the most common word order in main clauses in Middle Cornish was, in affirmative statements, SVO, with the verb in the third person singular:

My a wel an gath

1SG PTCL see-PRES.3SG DEF cat

'I see the cat.'

When affirmative statements are in the less common VSO order, they usually begin with an adverb or other element, followed by an affirmative particle, with the verb inflected for person and tense:

Ev a grys y hwelav an gath

3SG.M PTCL believe-PRES.3SG PTCL see-PRES.1SG DEF cat

'He believes that I see the cat.'

In negative statements, the order was usually VSO, with an initial negative particle and the verb conjugated for person and tense:

Ny welav an gath

NEG see-PRES.1SG DEF cat

'I do not see the cat.'

A similar structure is used for questions:

a glewsyugh why?

PTCL hear-PLUPERF.2PL 2PL

'Did you hear?'

Elements can be fronted for emphasis:

an gath my a wel

DEF cat 1SG PTCL see-PRES.3SG

'I see the cat.'

Sentences can also be constructed periphrastically using auxiliary verbs such as bos 'be, exist':

Yma ow kelwel ely

be-PRES-AFF.3SG PTCL call-VN Ely

'(He) is calling Ely.'

As Cornish lacks verbs such as 'to have', possession can also be indicated in this way:

'ma 'gen ehaz nyi dhen

be-PRES-AFF.3SG 1PL health 1PL to+us

'We have our health.'

Enquiring about possession is similar, using a different interrogative form of bos:

Hostes, ues boues dewhy?

Hostess be-PRES-INTERR-INDEF.3SG food to+you

'Hostess, have you [any] food?'

Nouns usually precede the adjective, unlike in English:

Benyn vas

woman good

'[A] good woman.'

Some adjectives usually precede the noun, however:

Drog den

evil man

'[An] evil man.'

Culture
The Celtic Congress and Celtic League are groups that advocate cooperation amongst the Celtic Nations in order to protect and promote Celtic languages and cultures, thus working in the interests of the Cornish language.

There have been films such as Hwerow Hweg, some televised, made entirely, or significantly, in Cornish. Some businesses use Cornish names.

Cornish has significantly and durably affected Cornwall's place-names as well as Cornish surnames and knowledge of the language helps the understanding of these ancient meanings. Cornish names are adopted for children, pets, houses and boats.

There is Cornish literature, including spoken poetry and song, as well as traditional Cornish chants historically performed in marketplaces during religious holidays and public festivals and gatherings.

There are periodicals solely in the language, such as the monthly An Gannas, An Gowsva and An Garrick. BBC Radio Cornwall has a news broadcast in Cornish and sometimes has other programmes and features for learners and enthusiasts. Local newspapers such as the Western Morning News have articles in Cornish, and newspapers such as The Packet, The West Briton, and The Cornishman have also been known to have Cornish features. There is an online radio and TV service in Cornish called Radyo an Gernewegva, publishing a one-hour podcast each week, based on a magazine format. It includes music in Cornish as well as interviews and features.

The language has financial sponsorship from sources including the Millennium Commission. A number of language organisations exist in Cornwall: Agan Tavas (Our Language), the Cornish sub-group of the European Bureau for Lesser-Used Languages, Gorsedh Kernow, Kesva an Taves Kernewek (the Cornish Language Board) and Kowethas an Yeth Kernewek (the Cornish Language Fellowship).

There are ceremonies, some ancient, some modern, that use the language or are entirely in the language.

Cultural events
Cornwall has had cultural events associated with the language, including the international Celtic Media Festival, hosted in St Ives in 1997. The Old Cornwall Society has promoted the use of the language at events and meetings. Two examples of ceremonies that are performed in both the English and Cornish languages are Crying the Neck and the annual mid-summer bonfires.

Since 1969, there have been three full performances of the Ordinalia, originally written in the Cornish language, the most recent of which took place at the plen-an-gwary in St Just in September 2021. While significantly adapted from the original, as well as using mostly English-speaking actors, the plays used sizable amounts of Cornish, including a character who spoke only in Cornish and another who spoke both English and Cornish. The event drew thousands over two weeks, also serving as a celebration of Celtic culture. The next production, scheduled for 2024, could, in theory, be entirely in Cornish, without English, if assisted by a professional linguist.

Outside of Cornwall, efforts to revive the Cornish language and culture through community events are occurring in Australia. A biennial festival, Kernewek Lowender, takes place in South Australia, where both cultural displays and language lessons are offered.

Study and teaching
Cornish is taught in some schools; it was previously taught at degree level at the University of Wales, though the only existing course in the language at university level is as part of a course in Cornish studies at the University of Exeter. In March 2008 a course in the language was started as part of the Celtic Studies curriculum at the University of Vienna, Austria. The University of Cambridge offers courses in Cornish through its John Trim Resources Centre, which is part of the university's Language Centre. In addition, the Department of Anglo-Saxon, Norse and Celtic (which is part of the Faculty of English) also carries out research into the Cornish language.

In 2015 a university-level course aiming at encouraging and supporting practitioners working with young children to introduce the Cornish language into their settings was launched. The Cornish Language Practice Project (Early Years) is a level 4 course approved by Plymouth University and run at Cornwall College. The course is not a Cornish-language course but students will be assessed on their ability to use the Cornish language constructively in their work with young children. The course will cover such topics as Understanding Bilingualism, Creating Resources and Integrating Language and Play, but the focus of the language provision will be on Cornish. A non-accredited specialist Cornish-language course has been developed to run alongside the level 4 course for those who prefer tutor support to learn the language or develop their skills for use with young children.

Cornwall's first Cornish-language crèche, Skol dy'Sadorn Kernewek, was established in 2010 at Cornwall College, Camborne. The nursery teaches children aged between two and five years alongside their parents to ensure the language is also spoken in the home.

A number of dictionaries are available in the various orthographies, including A Learners' Cornish Dictionary in the Standard Written Form by Steve Harris (ed.), An Gerlyver Meur by Ken George, Gerlyver Sawsnek–Kernowek by Nicholas Williams and A Practical Dictionary of Modern Cornish by Richard Gendall. Course books include the three-part Skeul an Yeth series, Clappya Kernowek, Tavas a Ragadazow and Skeul an Tavas, as well as the more recent Bora Brav and Desky Kernowek. Several online dictionaries are now available, including one organised by An Akademi Kernewek in SWF.

Classes and conversation groups for adults are available at several locations in Cornwall as well as in London, Cardiff and Bristol. Since the onset of the COVID-19 pandemic a number of conversation groups entitled Yeth an Werin Warlinen have been held online, advertised through Facebook and other media. A surge in interest, not just from people in Cornwall but from all over the world, has meant that extra classes have been organised.

Cornish studies
William Scawen produced a manuscript on the declining Cornish language that continually evolved until he died in 1689, aged 89. He was one of the first to realise the language was dying out and wrote detailed manuscripts which he started working on when he was 78. The only version that was ever published was a short first draft but the final version, which he worked on until his death, is a few hundred pages long. At the same time a group of scholars led by John Keigwin (nephew of William Scawen) of Mousehole tried to preserve and further the Cornish language and chose to write in Cornish. One of their number, Nicholas Boson, tells how he had been discouraged from using Cornish to servants by his mother. This group left behind a large number of translations of parts of the Bible, proverbs and songs. They were contacted by the Welsh linguist Edward Lhuyd, who came to Cornwall to study the language.

Early Modern Cornish was the subject of a study published by Lhuyd in 1707, and differs from the medieval language in having a considerably simpler structure and grammar. Such differences included sound changes and more frequent use of auxiliary verbs. The medieval language also possessed two additional tenses for expressing past events and an extended set of possessive suffixes.

John Whitaker, the Manchester-born rector of Ruan Lanihorne, studied the decline of the Cornish language. In his 1804 work the Ancient Cathedral of Cornwall he concluded that: "[T]he English Liturgy, was not desired by the Cornish, but forced upon them by the tyranny of England, at a time when the English language was yet unknown in Cornwall. This act of tyranny was at once gross barbarity to the Cornish people, and a death blow to the Cornish language."

Robert Williams published the first comprehensive Cornish dictionary in 1865, the Lexicon Cornu-Britannicum. As a result of the discovery of additional ancient Cornish manuscripts, 2000 new words were added to the vocabulary by Whitley Stokes in A Cornish Glossary. William C. Borlase published Proverbs and Rhymes in Cornish in 1866 while A Glossary of Cornish Names was produced by John Bannister in the same year. Frederick Jago published his English–Cornish Dictionary in 1882.

In 2002, the Cornish language gained new recognition because of the European Charter for Regional and Minority Languages. Conversely, along with government provision was the governmental basis of "New Public Management", measuring quantifiable results as means of determining effectiveness. This put enormous pressure on finding a single orthography that could be used in unison. The revival of Cornish required extensive rebuilding. The Cornish orthographies that were reconstructed may be considered versions of Cornish because they are not traditional sociolinguistic variations. In the middle-to-late twentieth century, the debate over Cornish orthographies angered more people because several language groups received public funding. This caused other groups to sense favouritism as playing a role in the debate.

A governmental policymaking structure called New Public Management (NPM) has helped the Cornish language by managing public life of the Cornish language and people. In 2007, the Cornish Language Partnership MAGA represents separate divisions of government and their purpose is to further enhance the Cornish Language Developmental Plan. MAGA established an Ad-Hoc Group, which resulted in three orthographies being presented. The relations for the Ad-Hoc Group were to obtain consensus among the three orthographies and then develop a "single written form". The result was creating a new form of Cornish, which had to be natural for both new learners and skilled speakers.

Recent Modern Cornish literature
In 1981, the Breton library Preder edited Passyon agan arluth (Passion of our lord), a 15th-century Cornish poem. The first complete translation of the Bible into Cornish, translated from English, was published in 2011. Another Bible translation project translating from original languages is underway. The New Testament and Psalms were posted on-line on YouVersion (Bible.com) and Bibles.org in July 2014 by the Bible Society.

A few small publishers produce books in Cornish which are stocked in some local bookshops, as well as in Cornish branches of Waterstones and WH Smith, although publications are becoming increasingly available on the Internet. Printed copies of these may also be found from Amazon. The Truro Waterstones hosts the annual Holyer an Gof literary awards, established by Gorsedh Kernow to recognise publications relating to Cornwall or in the Cornish language. In recent years, a number of Cornish translations of literature have been published, including Alice's Adventures in Wonderland (2009), Around the World in Eighty Days (2009), Treasure Island (2010), The Railway Children (2012), Hound of the Baskervilles (2012), The War of the Worlds (2012), The Wind in the Willows (2013), Three Men in a Boat (2013), Alice in Wonderland and Through the Looking-Glass (2014), and A Christmas Carol (which won the 2012 Holyer an Gof award for Cornish Language books), as well as original Cornish literature such as Jowal Lethesow (The Lyonesse Stone) by Craig Weatherhill. Literature aimed at children is also available, such as Ple'ma Spot? (Where's Spot?), Best Goon Brèn (The Beast of Bodmin Moor), three Topsy and Tim titles, two Tintin titles and Briallen ha'n Alyon (Briallen and the Alien), which won the 2015 Holyer an Gof award for Cornish Language books for children. In 2014 An Hobys, Nicholas Williams's translation of J. R. R. Tolkien's The Hobbit, was published.

An Gannas is a monthly magazine published entirely in the Cornish language. Members contribute articles on various subjects. The magazine is produced by Graham Sandercock who has been its editor since 1976.

Media
In 1983 BBC Radio Cornwall started broadcasting around two minutes of Cornish every week. In 1987, however, they gave over 15 minutes of airtime on Sunday mornings for a programme called Kroeder Kroghen ('Holdall'), presented by John King, running until the early 1990s. It was eventually replaced with a five-minute news bulletin called An Nowodhow ('The News'). The bulletin was presented every Sunday evening for many years by Rod Lyon, then Elizabeth Stewart, and currently a team presents in rotation. Pirate FM ran short bulletins on Saturday lunchtimes from 1998 to 1999. In 2006, Matthew Clarke who had presented the Pirate FM bulletin, launched a web-streamed news bulletin called Nowodhow an Seythen ('Weekly News'), which in 2008 was merged into a new weekly magazine podcast Radyo an Gernewegva (RanG).

Cornish television shows have included a 1982 series by Westward Television with each episode containing a three-minute lesson in Cornish. An Canker-Seth, an eight-episode series produced by Television South West and broadcast between June and July 1984, later on S4C from May to July 1985, and as a schools programme in 1986. Also by Television South West were two bilingual programmes on Cornish Culture called Nosweyth Lowen. In 2016 Kelly's Ice Cream of Bodmin introduced a light hearted television commercial in the Cornish language and this was repeated in 2017.

The first episode from the third season of the US television program Deadwood features a conversation between miners, purportedly in the Cornish language, but really in Irish. One of the miners is then shot by thugs working for businessman George Hearst who justify the murder by saying, "He come at me with his foreign gibberish."

A number of Cornish language films have been made, including Hwerow Hweg, a 2002 drama film written and directed by Hungarian film-maker Antal Kovacs and Trengellick Rising, a short film written and directed by Guy Potter.

Screen Cornwall works with Cornwall Council to commission a short film in the Cornish language each year, with their FilmK competition. Their website states "FylmK is an annual contemporary Cornish language short film competition, producing an imaginative and engaging film, in any genre, from distinctive and exciting filmmakers".

A monthly half-hour online TV show began in 2017 called An Mis (The Month). It contained news items about cultural events and more mainstream news stories all through Cornish. It also ran a cookery segment called "Kegin Esther" ('Esther's Kitchen').

Music
English composer Peter Warlock wrote a Christmas carol in Cornish (setting words by Henry Jenner). The Cornish electronic musician Aphex Twin has used Cornish names for track titles, most notably on his Drukqs album.

Several traditional Cornish folk songs have been collected and can be sung to various tunes. These include "An Awhesyth", "Bro Goth agan Tasow", and "Delkiow Sivy".

In 2018, the singer Gwenno Saunders released an album in Cornish, entitled Le Kov, saying: "I speak Cornish with my son: if you're comfortable expressing yourself in a language, you want to share it."

Place-names and surnames

The Cornish language features in the toponymy of Cornwall, with a significant contrast between English place-names prevalent in eastern Cornwall and Cornish place-names to the west of the Camel-Fowey river valleys, where English place-names are much less common. Hundreds of Cornish family names have an etymology in the Cornish language, the majority of which are derived from Cornish place-names. Long before the agreement of the Standard Written Form of Cornish in the 21st century, Late Cornish orthography in the Early Modern period usually followed Welsh to English transliteration, phonetically rendering C for K, I for Y, U for W, and Z for S. This meant that place names were adopted into English with spellings such as 'Porthcurno' and 'Penzance'; they are written Porth Kernow and Pen Sans in the Standard Written Form of Cornish, agreed upon in 2008. Likewise words such as Enys ('island') can be found spelled as Ince as at Ince Castle. These apparent mistransliterations can, however, reveal an insight into how names and places were actually pronounced, explaining, for example, how anglicised Launceston is still pronounced [ˈlansǝn] with emphasis on the first element, perhaps from Cornish Lann Stefan, though the Concise Oxford Dictionary of English Place-Names considers this unlikely.

The following tables present some examples of Cornish place names and surnames and their anglicised versions:

Samples
From the Universal Declaration of Human Rights:

From Bro Goth agan Tasow, the Cornish anthem:

From the wrestler's oath:

Dictionaries

 * Gerlyver kernewek (Cornish dictionary)
 * An English-Cornish Glossary in the Standard Written Form – Cornish Language Partnership
 * Lexicon Cornu-Britannicum: a Dictionary of the Ancient Celtic Language of Cornwall by Robert Williams, Llandovery, 1865.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Cornish language


text:
Talk:Cornish language

In case you're interested…
Hi, I wanted to let contributors to this article know that I have created a draft page about Cornish exonyms, called Draft:Cornish exonyms. Please feel free to add to the list. I hope it gets considered and added soon. Thanks! Gagana Ausetalia (talk) 12:57, 8 February 2022 (UTC) striked out edits by blocked sockpuppet –Austronesier (talk) 10:24, 12 February 2022 (UTC)
 * Great work! Perhaps I'll contribute if I have time... we already have Welsh exonyms, and I'm sure that your draft will be considered and added as soon as it's decent enough for article space. 😁👍  Tewdar   20:34, 8 February 2022 (UTC)

@Tewdar I recently became auto-confirmed (today) and I have moved the article to an actual page. Thanks for your contributions and I hope more users help contribute too. Gagana Ausetalia (talk) 06:14, 9 February 2022 (UTC)
 * Marvellous. Also well done for splitting the UK into its constituent nations - seems a sensible solution to me. The Williams UCR dictionary has a whole bunch of, erm, 'innovated' placenames in a divergent orthography, but I think his Desky Kernowek has a few too that could probably be adjusted to SWF orthography without too much controversy. Also, we could probably use a 'miscellaneous' section for stuff like seas and oceans. What do you think?   Tewdar   09:28, 9 February 2022 (UTC)
 * Unfortunately I hhad to delete it as block evasion. Graham 87 12:07, 11 February 2022 (UTC)

Revived language
How is the revival of Cornish going nowadays? The article mentions the efforts for reviving it in the 2000s and 2010s, mentioning the estimate of 557 speakers in 2011. Now, in the 2020s, can Cornish be added to the history of revived languages? The article states that there are already native speakers of Cornish, bilingual and also speaking English. If the language has native speakers after its extinction in the 18th century, can it be added to Language revitalization as a successfully revived language along with Modern Hebrew? 2804:14D:8084:8B09:E8BB:9B08:8CA2:CB69 (talk) 16:10, 2 May 2022 (UTC)

 * Lowena dhis! (Hello!) I believe there is already a section for Cornish at the Language revitalization article. The number of speakers is still small, but hopefully growing rather than shrinking.  Tewdar   16:54, 2 May 2022 (UTC)
 * The results for the 2021 census should be released within the next couple of months. Covid lockdown resulted in a lot of interest in people learning the language online (https://www.bbc.co.uk/news/uk-england-cornwall-60302511) so the language is certainly growing. I don't know about the number of native speakers, because speakers tend to be fragmented between different communities. Brwynog (talk) 10:09, 4 May 2022 (UTC)

 * The results have now been published. The number stating Cornish to be their "main language" was 564. Those may include L1 speakers as well as L2 speakers, but does not tell us how many fluent speakers there actually are. Cornwall Council states that "This figure should not be used to identify the number of Cornish speakers – it would be an underestimate as the Census only asked what people's main language is." Bodrugan (talk) 12:38, 15 June 2023 (UTC)
 * The idea that the language died seems to have been disproved, it might have been fingernail hanging on and a patois at the time of Henry Jenner et however at the time of the start of the rivial there were still native speakers 85.10.117.114 (talk) 17:49, 31 October 2023 (UTC)
 * Well that's what we call original research, taking matierial about the 2021 census and trying to exprapolate from that a new position (not found in the source material) that the Cornish language "must" never have really died out for a spell. In order for Wikipedia to say anything at all along the lines of "the idea that language died seems to have been disproved" we would need reliable sources that make this case convincingly, and even then we would have to attribute this idea as a statement of that/those source[s] viewpoint, since it directly conflicts with the view of previous reliable sources we've already cited.  — SMcCandlish ☏ ¢ 😼  17:55, 31 October 2023 (UTC)
 * Rod Lyon's book 'Cornish - the struggle for survival', published in 2001 by Taves an Werin, is a detailed look at who was able to speak Cornish from the time of Dolly Pentreath to the 1930s and at what level. Kensa Broadhurst at the University of Exeter is also conducting research into the same topic. Brwynog (talk) 04:22, 14 November 2023 (UTC)
 * I see Rod Lyon is a notable person, although surprisingly he trained as civil engineer rather than as a linguist. Would his book be considered WP:FRINGE? Martinevans123 (talk) 10:18, 16 April 2024 (UTC)
 * I am not sure it is quite fringe, but it is definitely one that needs careful evaluation. Does the writer and former Grand Bard have an agenda? Is there any peer evaluation of the claims? Sirfurboy🏄 (talk) 10:28, 16 April 2024 (UTC)
 * And having tried to access this source, it is not coming to anything. Couldn't find it listed for sale nor at any Library I have access to (haven't checked the National Library though). I found it in a Cornish archive though. So it is a 22 page pamphlet written by a former Grand Bard, published by Taves an Werin, which has no web presence but the name translates as "Tongue of the people" (tongue as in language) so it is a very small Cornish language / Cornish interest publisher. This is hardly the kind of neutral secondary source we need to make bold claims. In fact, we have been here before. See Talk:Cornish language/Archive 4 where I tracked down another booklet that made these claims. That one didn't pass muster, and this one is not going to either. Nothing to see here.So what about Kensa Broadhurst? Well this is more interesting. She is listed as a Ph.D. Student at University of Exeter here  and her bio tells us: So there may be something there. But we appear to be too soon on this one. If she successfully defends a thesis that the language never died out, then yes, we can use that thesis here. But at this stage she is still apparently working on the thesis. We will need to wait. Sirfurboy🏄 (talk) 12:15, 16 April 2024 (UTC)

Map, Britonia, etc.
The map appears to be based on a fictional book. I'll see if I can find a better one. If I can, it just needs to say 'probable Brittonic languages c. 600 AD', no need for any mention of textual evidenxe etc... what do others think?  Tewdar  12:03, 20 February 2023 (UTC)

 * Whether it is annotated or not, the shading on Galicia is a strong piece of visual information. As it is disputed, perhaps it should just go? Sirfurboy🏄 (talk) 12:32, 20 February 2023 (UTC)

 * I have no problem with removing the map entirely until a better source is found. I'll get rid of it, unless there are any objections?  Tewdar   12:39, 20 February 2023 (UTC)

 * I replaced it with the existing map showing the decline of the language.  Tewdar   14:13, 20 February 2023 (UTC)

Additional sources
This is material we should probably be using at some point:

— SMcCandlish ☏ ¢ 😼  05:52, 14 November 2023 (UTC)
 * – A short 22-page work. Doesn't seem to have an ISBN and may be difficult to find outside the UK. Lyon put out several of books of potential interest, including Gorseth Kernow: The Cornish Gorsedd What it is and What it Does (2008), Everyday Cornish (updated ed., 1984), Road-Names in Cornwall (1997, with Graham Sandercock), Notes on the Penwith Dialect of Cornish (2001), Colloquial Doesn't Mean Corrupt: Observations on contemporary Revived Cornish (2019), Notes on Spoken Cornish (1987, with John Pengilly). Those all show up on AbeBooks.co.uk right now, except for Cornish: The Struggle for Survival, the one most likely to be of use here, though Google indicates it has been for sale there in the past, so keep checking.
 * – Free full text of chapter.
 * – Free, full text. Weaker source, being only an MA thesis, but might have something of use, especially in its bibliography.
 * See also bibliography in: – Free full text of chapter. We're already citing this source itself, but it in turn cites many additional sources (may well be nearly all the relevant ones up to 2003; the bibliography is quite extensive).

In Devon
An anon added (with some punctuation correction imposed by me): Although it is spoken mainly in Cornwall, it also was spoken in the neighbouring County of Devon but went extinct in the 16th Century., with an edit summary of "I have added a new fact that is widely excepted and can be easily verified but searching it up on Google.I hope this edit is not undone as it is truthful and can be seen on a number of Websites". WP doesn't work on a "trust me, bro" basis, so of course this was reverted as unsourced. However, it is probably correct, in that Corwall used to include much of what is now Devonshire, and the language was surely spoken also in that area. So, something about this is probably worth sourcing and including. — SMcCandlish ☏ ¢ 😼  05:57, 9 December 2023 (UTC)

 * The lead would need to summarise something in the main text and at this point any such mention would contradict the main text which reads This is sourced to (George, 2009), who seems to be the source of the map on this page, and does indeed make the point that:(page 491). He also uses toponymic evidence to demonstrate the linguistic difference. Although there were no doubt some Cornish speakers in Devon, the extent of that would be highly speculative. The addition to the lead was wrong.
 * George, K. (2009) 'Cornish' in Ball, M. & Müller, N. eds. The Celtic Languages (2nd ed.). Hoboken: Taylor & Francis.
 * Sirfurboy🏄 (talk) 09:29, 9 December 2023 (UTC)

 * W. Devon has much in common with Cornwall, from the Tamar-based industries, Stannary parliaments and the "mining culture", but to say it has some sort of shared history with the Cornish language is dubious. The Devonians did not have the language grievances of the neighbouring Cornish during the Prayer Book Rebellion, for example.--SinoDevonian (talk) 22:20, 16 April 2024 (UTC)

Pronunciation
Anyone know why there are six unsourced pronunciation variants in the infobox? It's not even comprehensive, e.g. SWF (M) [kɛrˈnɔwɛk] is not listed, among other possible variations. Do we really need every possible permutation of [ɾ] and [ɹ]?  Tewdar  11:14, 17 March 2024 (UTC)

title: Talk:Cornish language


text:
Complexity theory

Complexity theory may refer to:

Science and technology

 * Computational complexity theory, a field in theoretical computer science and mathematics
 * Complex systems theory, the study of the complexity in context of complex systems
 * Assembly theory, a way of characterizing extraterrestrial molecular complexity to assess the probability of the presence of life

Other uses

 * Complexity economics, the application of complexity theory to economics
 * Complexity theory and organizations, the application of complexity theory to strategy

title: Complexity theory


text:
Talk:Complexity theory

Also
The study of complex systems is also called complexity theory, which is apparently quite a different subject then the one being discussed here.

Perhaps this article should be Computational Complexity Theory.

 * I've added a link at the bottom of the article. Feel free to write that up. I'd be very interested in reading an overview of that kind of complexity theory.  -LC

I always thought that NP-hard problems need not be decision problems. For instance, finding the shortest roundtrip in a weighted graph is NP-hard; deciding whether a roundtrip shorter than a given number exists is NP-complete. --AxelBoldt

 * Yes, that's right. The article doesn't say an NP-hard problem must be a "decision problem".  It just says it must be a "problem".  It's correct; it just didn't give much detail.  That paragraph also didn't use the word "reducibility", or distinguish the two types of reductions.  It also didn't describe when you'd be interested in polytime reductions (e.g. for NP-Hard), and when you'd be interested in something else (e.g. for P-Hard).

 * My intent was to put the details in the NP-Hard article which is linked to, but isn't written yet. Feel free to expand that paragraph, if you'd like.  Or write the NP-Hard article. - LC

Complexity
Where should the Complexity article fit on this disambiguation page? - Theboywonder 07:29, 19 October 2005 (UTC)

 * Duplicate. Sorry. (Theboywonder 14:20, 19 October 2005 (UTC))

title: Talk:Complexity theory


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Charybdis

Charybdis (Khárybdis, ;, ) is a sea monster in Greek mythology. Charybdis, along with the sea monster Scylla, appears as a challenge to epic characters such as Odysseus, Jason, and Aeneas. Scholarship locates her in the Strait of Messina.

The idiom "between Scylla and Charybdis" has come to mean being forced to choose between two similarly dangerous situations.

Description
The sea monster Charybdis was believed to live under a small rock on one side of a narrow channel. Opposite her was Scylla, another sea monster, who lived inside a much larger rock. The sides of the strait were within an arrow-shot of each other, and sailors attempting to avoid one of them would come in reach of the other. To be "between Scylla and Charybdis" therefore means to be presented with two opposite dangers, the task being to find a route that avoids both. Three times a day, Charybdis swallowed a huge amount of water, before belching it back out again, creating large whirlpools capable of dragging a ship underwater. In some variations of the story, Charybdis was simply a large whirlpool instead of a sea monster.

Through the descriptions of Greek mythical chroniclers and Greek historians such as Thucydides, modern scholars generally agree that Charybdis was said to have been located in the Strait of Messina, off the coast of Sicily and opposite a rock on the mainland identified with Scylla. A whirlpool does exist there, caused by currents meeting, but it is dangerous only to small craft in extreme conditions.

Family
Another myth makes Charybdis the daughter of Poseidon and Gaia and living as a loyal servant to her father.

Origin
Charybdis aided her father Poseidon in his feud with her paternal uncle Zeus and, as such, helped him engulf lands and islands in water. Zeus, angry over the land she stole from him, sent her to the bottom of the sea with a thunderbolt; from the sea bed, she drank the water from the sea thrice a day, creating whirlpools. She lingered on a rock with Scylla facing her directly on another rock, making a strait.

In some myths, Charybdis was a voracious woman who stole oxen from Heracles, and was hurled by the thunderbolt of Zeus into the sea, where she retained her voracious nature.

The Odyssey
Odysseus faced both Charybdis and Scylla while rowing through a narrow channel. He ordered his men to avoid Charybdis, thus forcing them to pass near Scylla, which resulted in the deaths of six of his men. Later, stranded on a raft, Odysseus was swept back through the strait and passed near Charybdis. His raft was sucked into her maw, but he survived by clinging to a fig tree growing on a rock over her lair. On the next outflow of water, when his raft was expelled, Odysseus recovered it and paddled away safely.

Jason and the Argonauts
The Argonauts were able to avoid both dangers because Hera ordered the Nereid Thetis to guide them through the perilous passage.

The Aeneid
In the Aeneid, the Trojans are warned by Helenus of Scylla and Charybdis, and are advised to avoid them by sailing around Pachynus point (Cape Passero) rather than risk the strait. Later, however, they find themselves passing Etna, and have to row for their lives to escape Charybdis.

Aesop
Aristotle mentions in his Meteorologica that Aesop once teased a ferryman by telling him a myth concerning Charybdis. With one gulp of the sea, she brought the mountains to view; islands appeared after the next. The third is yet to come and will dry the sea altogether, thus depriving the ferryman of his livelihood.

title: Charybdis


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Talk:Charybdis

Charybdis and Chalybes
It is possible that Charybdis was the mutation of Chalybians or Chalybes (a people lived at coast of northern Asia Minor, compare Halybe of Homer)).

Scylla was the mutation of Scolotians or Scoloti (a Schythian people lived at European-Thracian coast of Black Sea).

Both were the terror of sailors who have been travelled across Bosporus, in during of 2nd/1st millennium B.C.

--IonnKorr 15:25, 31 October 2005 (UTC)

Odyssey
Is it worth mentioning that the Charybdis is one of the major trials faced by Odysseus? — Ilyan e  p   (Talk)  01:15, 6 January 2006 (UTC)

"Odysseus was not so fortunate; he chose to risk Scylla at the cost of some of his crew rather than lose the whole ship to Charybdis. (Homer's Odyssey, Book XII)." It already has been.
 * At this time, the article text does refer to Charybdis as a "trial of Odysseus" -- paragraph beginning "Stranded on a makeshift raft, ..." (there's much more that's been included). So it's been taken care of.  Dave Fafarman (talk) 18:18, 12 December 2007 (UTC)

Contradiction
"In Greek mythology, Charybdis or Kharybdis ("sucker down", Greek — Χάρυβδις) was a sea monster, daughter of Poseidon and Gaia." and "Charybdis was originally a sea-nymph who flooded land to enlarge her father's underwater kingdom, until Zeus turned her into a monster." Is a daughter of Gaia and Poseidon a sea-nymph?--Randalllin 07:03, 20 December 2006 (UTC)

The children of Posieden are usually cyclopes(child of Poseiden & a wood-nymph) or sea-nymphs(child of Poseiden & a goddess). I think Gaia is the mother of the titans but she counts as a goddess. She is the grandmother of the gods. 66.143.165.58 01:48, 21 December 2006 (UTC)Jadee

Slightly disturbed by this sentence. It smacks of someone trying to sneak something obscene into a wiki entry. I'm not an expert in mythology, but I'm pretty sure this is highly inaccurate.

"She swallows huge amounts of water three times a day and then belches them back out again creating whirlpools."

CThornett 17:05, 1 March 2007 (UTC)

Actually, this is an accurate description (though a bit blunt). The version I read said "spits it up again", but it's the same thing. 24.167.67.174 23:38, 22 April 2007 (UTC)

Pronunciation
Anyone know how Charybdis is usually pronounced by anglophones? --Surturz 04:23, 12 March 2007 (UTC)
 * According to Gods, Demigods & Demons: An Encyclopedia of Greek Mythology by Bernard Evslin, "kuh RIB dihss". --OGoncho 23:34, 19 May 2007 (UTC)

Deletion of Homer's Odyssey: The Voyage Home
Why was "Homer's Odyssey: The Voyage Home" deleted from this article? This was a radio drama version of the epic poem by Homer which prominently featured the monster Charybdis. This article includes many instances in which Charybdis is referenced in popular culture, including video games, films, books and popular music. This was a radio drama retelling of the Charybdis story from Homeric myth, as heard on XM Satellite Radio -- how was it irrelevant to the subject matter? Soundout (talk) 00:57, 16 September 2008 (UTC)

II haven't seen the original article where this was actually a part of, but I must agree on one thing: Homer's Odyssey is including Charybdis as a prominent character. I didn't know about her until I had to read about her (in Latin class) in connection with the Odyssey. Janet1983 (talk) 01:23, 11 August 2010 (UTC)

Whirlpool
Wasn't the myth of Charybdis based upon a whirlpool that actually appears in the straits between Sicily and Italy?

I think it's the other way round - there were legends about the straits of Scylla and Charybdis that were applied to the Straits of Messina when the Greeks discovered it and applied existing myths to new areas - the text of the Odyssey suggests there was no significant knowledge of the Western Mediterranean at the time of the the Trojan War so it is more likely that legends associated with it and the hero' return home would have originated somewhere within the Greek's known world. (And in the Jason & the Argonauts story which also features Scylla, the Argo was sailing down the Adriatic sea.) The channel between the island of Levkas and the mainland of Greece has been suggested - the headland near the entrance is called Cape Skilla and there's a mountain overlooking the channel called Lamia - which was a long necked monster that attacked the hero... As the channel is now blocked up by a causeway it's impossible to tell if there was ever a whirlpool, but the local tides could have created one such as Homer describes. — Preceding unsigned comment added by Shawn Baggett (talk • contribs) 10 Dec. 2014

title: Talk:Charybdis