Examples: cartography card archaeology archetype monarchy legal loyal purse personal cinema kinase car carpenter hippopotamus Mesopotamia dative data date
...
Proto-Celtic *writ-

→ Welsh wrth (inherited)
→ Welsh gwrth- (inherited)
→ Irish le (inherited)
→ Irish frith- (inherited)
→ Irish fré (inherited)
→ Middle Irish fri (inherited)
→ Old Irish fri (inherited)
→ Old Irish frith- (inherited)