Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Saterland Frisian
Hälper
←
English
helper
(cognate)
←
Proto-West Germanic
*helpārī
(inherited)
←
Old Frisian
helpere
(inherited)
←
Saterland Frisian
Hälpe
(affix)
←
Saterland Frisian
-er
(affix)
→
English
helper
(cognate)