Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Norwegian
-s
←
Proto-Germanic
*sek
(inherited)
←
Old Norse
-sk
(inherited)
←
Old Norse
-s
(inherited)
→
English
-'s
(cognate)