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

→ Breton gwir (inherited)
→ Welsh gwir (inherited)
→ Welsh cywir (mention)
→ Irish cóir (mention)
→ Irish fíor (inherited)
→ Scottish Gaelic fìor (inherited)
→ Old Irish fír (inherited)