Examples: cartography card archaeology archetype monarchy legal loyal purse personal cinema kinase car carpenter hippopotamus Mesopotamia dative data date
...
Welsh -au
← Breton -où (cognate)
← Proto-Brythonic *-ow (inherited)
← Proto-Celtic *-owes (inherited)
← Cornish -ow (cognate)
← Old Welsh -ou (inherited)
← Middle Welsh -eu (inherited)

→ Breton -où (cognate)
→ Welsh bachgennesau (affix)
→ Welsh eisteddfodau (affix)
→ Welsh Cymraesau (affix)
→ Welsh llannau (affix)
→ Welsh sigaretau (affix)
→ Welsh rhefrau (affix)
→ Welsh teisennau (affix)
→ Welsh treigladau (affix)
→ Welsh mamau (affix)
→ Welsh lloerau (affix)
→ Welsh afalau (affix)
→ Welsh tadau (affix)
→ Welsh soddgrythau (affix)
→ Welsh basgrythau (affix)
→ Welsh ebolesau (affix)
→ Welsh enwau (affix)
→ Welsh llysfamau (affix)
→ Welsh llystadau (affix)
→ Welsh broliannau (affix)
→ Welsh boreau (affix)
→ Welsh abadau (affix)
→ Welsh dyrnau (affix)
→ Welsh rhodau (affix)
→ Welsh pethau (affix)
→ Welsh hafau (affix)
→ Welsh gaeafau (affix)
→ Welsh gwanwynau (affix)
→ Welsh athrawesau (affix)
→ Welsh prifathrawesau (affix)
→ Welsh costau (affix)
→ Welsh prifgostau (affix)
→ Welsh llythyrau (affix)
→ Welsh llythyrennau (affix)
→ Welsh priflythyrennau (affix)
→ Welsh odlau (affix)
→ Welsh prifodlau (affix)
→ Welsh gwelyau (affix)
→ Welsh cysyniadau (affix)
→ Welsh rhosynnau (affix)