Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Occitan
lenga
←
Proto-Indo-European
*dn̥ǵʰwéh₂s
(inherited)
←
Old Latin
dingua
(inherited)
←
Proto-Italic
*denɣwā
(inherited)
←
Latin
lingua
(inherited)
←
Old Occitan
lengua
(inherited)
→
French
langue
(cognate)
→
Portuguese
língua
(cognate)