Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Occitan
clau
←
Latin
clāvis
(inherited)
←
Old Occitan
clau
(inherited)
→
Catalan
clau
(cognate)
→
Catalan
clau
(cognate)
→
Occitan
clavar
(suffix)
→
Portuguese
chave
(cognate)