Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Manx
do-
←
Old Irish
do-
(inherited)
←
Old Irish
du-
(mention)
→
Manx
do-varganagh
(affix)
→
Manx
do-smooinaghtyn
(affix)