9. _ŏ_, obscure, as _o_ in _London_, _ton_, etc.
14. _y_, short, as _y_ in _carry_, _marry_, etc. This is used chiefly as an unaccented final in a word of more than one syllable.
In the case of the letter _y_, there is a variation of sound in such monosyllables as _nŷ_, _whŷ_, _jŷ_, _hŷ_ under certain circumstances. In this system of spelling the circumflex is omitted when these words are enclitic.
Of these, _aw_, _ai_, _ei_, _ay_, _ey_, _ou_, are only repetitions of the simple vowels _ô_, _û_, and _ŷ_. The other four have sounds not otherwise represented.
1. _aw_ has the same sound as _ô_. It is very rarely used.
2. _ai_, _ay_, _ei_, _ey_, have nearly the same sound as _ŷ_, rather more diphthongalised.
3. _eu_, _ew_ have the sound of _ew_ in the English word _dew_, the usual English long _u_. This sound is also represented in Cornish by _y_ consonant followed by _u_, as in the word _yu_, is, which has exactly the sound of the English personal pronoun _you_.
4. _oi_, _oy_ have the sound of _oy_ in _boy_.
5. _Ow_ has two sounds—(1) as an unaccented final, as _o_ in _bone_. This is also its sound when it occurs without any consonant, in the possessive pronoun _ow_, my, and the participle particle _ow_; (2) in other cases it sounds as _ou_ in _you_, and rarely as _ow_ in _now_.
6. _Ou_ has the same sound as _û_, and as the second sound of _ow_. It is the regular symbol for that sound in Breton, and very commonly in the Cornish dramas, where, as in Breton, _u_ commonly represented, approximately, the French _u_, which later became _î_ or _ew_.
In the Middle Cornish manuscripts the vowels are represented in various ways, and there is a special uncertainty about unaccented and obscure vowels.
Vowels were sometimes lengthened by doubling, or by adding a _y_, and rarely, until Jordan’s _Creation_, by adding a mute _e_ after the closing consonant; but often quantity was not indicated at all.
Long _î_ (_ee_ in _see_) was more often than not represented by _y_, but, as in Welsh, _y_ not infrequently represented the obscure vowel (_u_ in _until_), and often a sound which later became a short _e_, but in unaccented syllables was, as is not unusually the case in English, more of the nature of the obscure vowel, or perhaps something between that and a short _i_. Indeed all unaccented vowels tend to become obscure, very much as they do in English, and hence are variously expressed.