kukati

1. colloq. to complain; to whine; to moan
   Stalno kuka da nema para. — He's always moaning that he has no money.
   Prestani da kukaš i uradi nešto. — Stop whining and do something.
2. to lament; to wail
   Žene su kukale nad pokojnikom. — The women were wailing over the dead man.
3. (of a cuckoo) to cuckoo
   U šumi je kukala kukavica. — A cuckoo was calling in the woods.

What someone complains about follows na + accusative (kuka na platu) or a da-clause.