beskorisno

1. uselessly; to no purpose
   Ceo dan sam beskorisno proveo na telefonu. — I wasted the whole day on my phone.
2. (beskorisno je + inf.) it's useless; it's pointless
   Beskorisno je raspravljati s njim. — It's pointless arguing with him.
   Zvao sam ga deset puta, ali bilo je beskorisno. — I called him ten times, but it was no use.