Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Kashubian
chtos
←
Belarusian
хтось
(cognate)
←
Kashubian
chto
(suffix)
←
Kashubian
-s
(suffix)
←
Polish
ktoś
(cognate)