Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Bulgarian
начатък
←
Bulgarian
наче́на
(affix)
←
Bulgarian
-тък
(affix)
←
Proto-Slavic
*načętъkъ
(inherited)