Questions & Answers about Ako čaša pukne, uzet ću drugu.
Why is it pukne and not puca?
Because pukne comes from the perfective verb puknuti, which refers to a single completed event: to break / to crack.
In this sentence, the idea is if the glass breaks at some point, so Croatian normally uses the perfective present in the ako clause:
- Ako čaša pukne... = If the glass breaks...
By contrast, puca comes from the imperfective verb pucati, which suggests an ongoing, repeated, or habitual action:
- Čaša puca. = The glass is cracking / keeps cracking
- Čaše pucaju lako. = Glasses break easily
So pukne is the natural choice here because the sentence is about one possible future event.
Why is the verb after ako in the present tense if the meaning is future?