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

→ English often (mention)
→ English oft (inherited)
→ German oft (mention)
→ North Frisian oftem (derived)
→ Old Norse opt (mention)
→ Saterland Frisian oafte (derived)