opominjati

1. to warn; to remind
   Mama me stalno opominje da ponesem jaknu. — Mom keeps reminding me to take a jacket.
   Lekari opominju da je vrućina opasna za starije. — Doctors warn that the heat is dangerous for the elderly.
2. to reprimand; to rebuke
   Učiteljica ga je opominjala zbog pričanja na času. — The teacher kept reprimanding him for talking in class.

Constructions: opominjati koga na nešto (remind of) or opominjati koga zbog nečega (reprimand for).