Examples: cartography card archaeology archetype monarchy legal loyal purse personal cinema kinase car carpenter hippopotamus Mesopotamia dative data date
...
Portuguese carvão
Proto-Indo-European *ker (derived)
Latin carbo (inherited)
Portuguese carbono (doublet)
Old Portuguese carvon (inherited)

Friulian cjarbon (cognate)
Friulian cjarvon (cognate)
Galician carbón (cognate)
Portuguese carbono (doublet)