obnoviti

1. to restore; to rebuild; to renovate
   Posle rata su obnovili most. — After the war they rebuilt the bridge.
   Obnovili smo staru kuću na selu. — We renovated the old house in the village.
2. to resume; to renew
   Dve zemlje su obnovile diplomatske odnose. — The two countries resumed diplomatic relations.
   Firma mu je obnovila ugovor na još godinu dana. — The company renewed his contract for another year.
3. (obnoviti godinu) to repeat a year
   Pao je tri ispita i obnovio godinu. — He failed three exams and had to repeat the year.
4. (of knowledge) to revise; to brush up on
   Pre ispita sam obnovio celo gradivo. — Before the exam I revised all the material.
5. (of strength, supplies) to restore; to replenish
   Posle odmora je obnovio snagu i vratio se na posao. — After the holiday he restored his strength and went back to work.
   Prodavnica je obnovila zalihe pred praznike. — The shop replenished its stock before the holidays.

The imperfective is obnavljati.