Questions & Answers about Kad budemo došli u hotel, prvo ćemo otići na recepciju.
Because Serbian normally uses Future II in a time clause introduced by kad when talking about something that will be completed before another future action.
So the structure is:
- kad budemo došli = when we have arrived / when we arrive
- otići ćemo = we will go
In standard Serbian, kad ćemo doći would usually mean something more like when will we come?, not when we come.
So in this sentence:
- Kad budemo došli u hotel = When we arrive at the hotel
- prvo ćemo otići na recepciju = we’ll first go to the reception desk
It is Future II.
Future II is formed with:
- a future form of biti (budem, budeš, bude, budemo, budete, budu)
- plus the l-participle of the main verb
Here:
- budemo = we will be
- došli = participle of doći (to come / arrive)
Together, budemo došli means something like we will have arrived or, more naturally in English here, when we arrive.