vladanje

1. behaviour; conduct
   Dobio je jedinicu iz vladanja. — He got the lowest grade for conduct.
   Njeno vladanje na poslu je besprekorno. — Her conduct at work is impeccable.
2. (+ instr.) command; proficiency
   Traži se odlično vladanje engleskim jezikom. — Excellent command of English is required.
3. rule; reign
   Za vreme njegovog vladanja zemlja se razvila. — The country developed during his rule.

In the sense of proficiency it takes the instrumental: vladanje jezikom.