Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Cornish
dyw
→
Cornish
dywvregh
(prefix)
→
Cornish
dyw-
(mention)
→
Cornish
dywvron
(prefix)