Futur 2 — Kada i Ako

English says "When we have finished our coffee, we will run to the shop" — present-ish in the first half, future in the second. Serbian does something different and more logical: the clause that comes first goes into futur drugi, and the main clause into ordinary future.

Futur 2 is built from budem, budeš, bude, budemo, budete, budu plus the same l-participle you already use for the past tense. That's the whole recipe — budem radio, budeš videla, budemo bili.

One nuance you'll feel rather than memorise: the participle can be perfective or imperfective, and it changes the picture. Kada budemo kupovali kafu means while we're in the middle of buying it; kada ih budemo sačekali means once we've finished waiting. Same tense, different camera angle.

The story below is a maze puzzle — read it as a route, and the blanks will make more sense.