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

→ English ea (inherited)
→ English yeo (inherited)
→ English Aa (derived)
→ Old English ea (inherited)
→ German Eisenach (derived)
→ Old Dutch golda (mention)
→ Saterland Frisian Äi (inherited)