Examples: cartography card archaeology archetype monarchy legal loyal purse personal cinema kinase car carpenter hippopotamus Mesopotamia dative data date
...
Welsh cath
← Proto-Brythonic *kaθ (inherited)
← Proto-Celtic *kattā (inherited)

→ English cat (cognate)
→ Welsh cathod (affix)
→ Welsh cathbysgod (affix)
→ Welsh cathau (affix)
→ Welsh cethin (affix)
→ Old Armenian կատու (cognate)