Examples: cartography card archaeology archetype monarchy legal loyal purse personal cinema kinase car carpenter hippopotamus Mesopotamia dative data date
...
Welsh dat-
← Cornish das- (cognate)

→ Welsh datblygu (affix)
→ Welsh datguddio (affix)
→ Welsh datgan (prefix)
→ Welsh datrys (prefix)
→ Welsh datgelu (prefix)