zabranjivati

1. to forbid; to prohibit
   Roditelji mu zabranjuju da izlazi noću. — His parents forbid him to go out at night.
   Zašto mi stalno nešto zabranjuješ? — Why are you always forbidding me things?
2. (of law, authorities) to ban; to outlaw
   Novi zakon zabranjuje pušenje u kafićima. — The new law bans smoking in cafés.

The person is in the dative, the thing in the accusative or da + present: zabranjivati deci slatkiše, zabranjivati nekome da puši.