Breakdown of Koristi zvono dok voziš na biciklističkoj stazi.
na
on, at / to, onto (with motion) / about (thinking about)
voziti
to drive / to ride (a snowboard, skis)
dok
while
koristiti
to use
Questions & Answers about Koristi zvono dok voziš na biciklističkoj stazi.
Is koristi the present tense or a command here?
It is a command (the imperative form). For the verb koristiti (to use), the second-person singular command (you, use!) and the third-person singular present tense (he/she uses) are identical: koristi. Context tells you this is an instruction.
Why does the sentence just say voziš instead of explicitly saying 'riding a bike'?
In Croatian, the verb voziti covers both driving a car and riding a bike. Because you are on a biciklističkoj stazi (cycling path), the context makes it obvious that you are cycling. You don't need to add the word bicikl as an object.
Could I use za vrijeme instead of dok to say 'while' in this sentence?
No, because za vrijeme means 'during' and must be followed by a noun, such as za vrijeme vožnje (during the ride). Because the sentence uses a conjugated verb (voziš), you must use the conjunction dok (while).
Why is biciklističkoj stazi in the locative case rather than the accusative?
The preposition na takes the locative case when an action happens continuously within a location. Since you are already riding along the path, it takes the locative. If you used the accusative (na biciklističku stazu), it would imply motion directed onto the path, such as turning onto it from the road.