Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Cornish
peswar
←
Proto-Brythonic
*pedwar
(inherited)
←
Proto-Celtic
*kʷetwares
(inherited)
←
Proto-Indo-European
*kʷetwóres
(inherited)
→
Cornish
peswora
(affix)
→
Cornish
peswar ugens
(compound)
→
Cornish
nownsek ha peswar ugens
(compound)