Kernewek Kemmyn was developed, mainly by Ken George, from Unified Cornish in 1986. It takes much of its inspiration from medieval sources, particularly Cornish passion plays, as well as Breton and to a lesser extent Welsh. It was subsequently adopted by the Cornish Language Board as their preferred system. It retained a Middle Cornish base but made the spelling more systematic by applying phonemic orthographic theory, and for the first time set out clear rules relating spelling to pronunciation. Before the Standard Written Form was introduced in 2008, users of KK[who?] claimed that the orthography had been taken up enthusiastically by the majority of Cornish speakers and learners, and advocates[who?] of this orthography claimed that it was especially welcomed by teachers, however a survey in 2008 indicated that KK users only made up roughly half of all Cornish speakers  After KK's introduction, many Cornish speakers chose to continue using Unified Cornish, and many moved to Revived Late Cornish.
The orthography has drawn heavy criticism from some areas. Since the publication of the Gerlyver Kernewek Kemmyn (dictionary), several writers have condemned the new orthography (Penglase 1994; Williams 1996; Mills 1999). Some supporters of KK claim that its phonetic spelling makes it easier to teach, and that its reconstructed phonology is grounded in the historic corpus of medieval Cornish literature.
Notably several writers have criticised George's reconstructed phonology, claiming it to be academically unsound. In 1994, Charles Penglase berated the lack of authenticity in KK resulting out of George's purely conjectural reconstruction of Middle Cornish phonology. In 1995, Nicholas Williams listed some 25 ways in which he believes the phonology and spelling of KK to be erroneous. In 1999, Jon Mills gives examples of numerous inaccuracies in George's data and shows how the English translation equivalents and neologisms given in the Gerlyver Kernewek Kemmyn entail a contrastive lexicology that is at odds with traditional practice as attested in the historical corpus of Cornish.
Another issue, which has caused controversy is that of Cornish placenames. In many instances, there are multiple, conflicting etymologies and possible meanings, but KK has tended to respell these according to one theory or another. This respelling not only can obscure an alternative origin or meaning, but is not always in line with the practice of other forms of revived Cornish.
While its users claim it to be the largest, and so most successful, variety of Cornish, a survey in 2008  indicated that KK users only make up roughly half of all Cornish speakers. Despite this, it has drawn heavy criticism from some areas, particularly its rival forms, Unified Cornish (Unyes) and Modern Cornish.
In 1987 Kesva an Taves Kernewek (Cornish Language Board) voted to adopt the Kernewek Kemmyn form of Cornish as its standard.
While the various varieties of revived Cornish have had a rocky relationship with one another, this has had the positive effect of creating a publishing and writing boom in Cornish. All of them have been used in constructing the Cornish language Wikipedia, and also in Gorseth Kernow, the Cornish Gorsedd.
Phonetics and phonology
The pronunciation of traditional Cornish is a matter of conjecture, but users of Revived Middle Cornish are more or less agreed about the phonology they use.
This is a table of the phonology of Revived Middle Cornish (RMC) as recommended for the pronunciation of Kernewek Kemmyn orthography, using symbols from the International Phonetic Alphabet (IPA).
|Nasal||m [m]||n [n]||ng [ŋ]|
|Stop||p [p]||b [b]||t [t]||d [d]||k [k]||g [g]|
|Affricate||ch [tʃ]||j [dʒ]|
|Fricative||f [f]||v [v]||th [θ]||dh [ð]||s [s]||s [z]||gh [x]||h [h]|
|r [ɾ]||y [j]||hw [ʍ]||w [w]|
These are tables of the phonology of Revived Middle Cornish as recommended for the pronunciation of Kernewek Kemmyn, using symbols from the International Phonetic Alphabet (IPA).
|Front||Near- front||Central||Near- back||Back|
|Front||Near- front||Central||Near- back||Back|
Speakers who prefer a later pronunciation merge the rounded vowels with the unrounded one.
The vowels with their corresponding letters in the Kernewek Kemmyn orthography and the short/long pairs are as follows:
|a ~ aː||ɛ ~ ɛː||œː||iː||ɔ ~ ɔː||ɤ ~ oː||uː||yː||ɪ ~ ɪː|
1. A vowel is considered short when it comes before double consonants (e.g. ⟨nn⟩, ⟨mm⟩, and so on), or before any two consonants.
3. ⟨e⟩ is pronounced as [ɛ] before double consonants and in unstressed syllable, and is geminated elsewhere.
4. Some vowels have a tendency to be reduced to schwas [ə] in unstressed syllables
- Cornish Language Partnership (2008)"A Report on The Cornish Language Survey" Available: www.magakernow.org.uk .
- Charles Penglase, "Authenticity in the Revival of Cornish", in Cornish Studies. Second series: Two. Exeter: University of Exeter Press. Pp. 96-107. ISBN 0-85989-454-1
- Nicholas Williams, Cornish Today: an examination of the revived language. FIrst and second editions: Sutton Coldfield: Kernewek dre Lyther, 1995; Third edition: Westport: Evertype, 2006. ISBN 978-1-904808-07-7
- Jon Mills, “Reconstructive Phonology and Contrastive Lexicography: Problems with the Gerlyver Kernewek Kemmyn”, in Cornish Studies. Second series: Seven. Exeter: University of Exeter Press. Pp. 193-218. ISBN 0-85989-644-7
- Jon Mills, “Reconstructive Phonology and Contrastive Lexicography: Problems with the Gerlyver Kernewek Kemmyn” in Cornish Studies. Second series: Seven. Exeter: University of Exeter Press. Pp. 193-218. ISBN 0-85989-644-7
- Cornish Language Partnership(2008) "A Report on The Cornish Language Survey" Available: www.magakernow.org.uk