određivati

1. to set; to fix
   Ko određuje cene u ovoj prodavnici? — Who sets the prices in this shop?
   Direktor određuje rokove za svaki projekat. — The director sets the deadlines for each project.
2. to determine; to shape
   Geni određuju boju očiju. — Genes determine eye colour.
   Novac često određuje naše odluke. — Money often determines our decisions.
3. to determine; to define
   Telefon sam određuje tvoju lokaciju. — The phone determines your location by itself.
4. (someone for a role or task) to appoint; to designate
   Trener određuje kapitena ekipe. — The coach appoints the team captain.
   Šef svako jutro određuje ko će raditi na terenu. — The boss decides every morning who will work in the field.

The perfective is odrediti.