Examples: cartography card archaeology archetype monarchy legal loyal purse personal cinema kinase car carpenter hippopotamus Mesopotamia dative data date
...
Belarusian -ся
Old East Slavic сѧ (inherited)
Proto-Slavic *sę (inherited)

Belarusian заставацца (affix)
Belarusian застацца (affix)
Belarusian радзіцца (affix)
Belarusian спускацца (affix)
Belarusian спусціцца (affix)
Belarusian смяяцца (mention)
Belarusian вучыцца (affix)