viknuti

1. to shout; to cry out
   Neko je viknuo moje ime iz gomile. — Someone shouted my name from the crowd.
   Viknula je „Stani!“ i potrčala za njim. — She shouted "Stop!" and ran after him.
2. (viknuti na + acc.) to yell at; to snap at
   Izvini što sam viknuo na tebe. — Sorry I yelled at you.

To yell at someone uses "na" + accusative: viknuti na dete.