Publication of the second edition of Gerlyver Kescows in printed form is expected once the new Gerlyver Brâs has been finalized. Meanwhile the full text of the Checklist of Mutations appears below. This may be modified from time to time in the light of comments. So if you are supportive of revived traditional Cornish and the Kernowek Standard spelling system, please let us know in the event you find any errors or think something might be improved. Go to Contact Us.

Last updated: 13 September 2022 (10:00)


Second state (lenition)

b > v

c >

Optionally no change after s, th

ch > j

d > dh

No change before û when pronounced yoo

Occasionally no change after s: e.g. nos, tus

g > zero

gl, gr often unchanged, but , but glân > lân is regular

growedha / groweth / grugys > wrowedha / wroweth / wrugys

Monosyllables usually unchanged, e.g. gis

And many loan-words also resist this change

go > wo

goo > woo

gou > wou

gu > wu



gw > w

k > g

Optionally no change after s, th

m > v

p > b

Optionally no change after s, th

qw > g

Optionally no change after s, th

t > d

Optionally no change after s, th

In Welsh loan-words go sometimes > o: e.g. arolegyth, an orseth

Second state in speech but not in writing

f > v in a few words: the most common are fordh, fos 

fl, fr unchanged

Some also argue for s > z. But the evidence for such a regular mutation is not strong. The pronunciation of s as [z] is better regarded as a matter determined primarily by phonetic environment and regional variation.

Third state (spirantization)

c > h

cl, cr unchanged 

> h kn unchanged

qw > wh

p > f

t > th

Fourth state (provection)

b > p

d > t

g > c / k

gw > qw

Fifth state (mixed)
b > f

> v after th

But note irregular re’th fo (re’ fo) in wishes

d > t

g > h

gl, gr unchanged

go > who

> wo after th

goo > whoo

> woo after th

gou > whou

> wou after th

gu > whu

> wu after th

> whù

> after th

> whû

> after th

gw > wh

> w after th

m > f 

> v after th

Note the unique nasal mutation dor > an nor (in special sense ‘earth as opposed to heaven’). The development d > j after n in a few words (an jëdh, a’n jeves etc) is sometimes called nasal mutation because it is triggered by n although the result of the change is not itself a nasal.