Examples: cartography card archaeology archetype monarchy legal loyal purse personal cinema kinase car carpenter hippopotamus Mesopotamia dative data date
...
Welsh gwerthu
Breton gwerzhañ (cognate)
Welsh gwerth (affix)
Welsh -u (affix)
Cornish gwertha (cognate)

Breton gwerzhañ (cognate)
Welsh peiriant gwerthu (affix)
Welsh arwerthu (affix)
Welsh gwerthiant (affix)
Welsh gwerthwr (affix)
Welsh mân-werthu (affix)