Learn Croatian: Proba za nastup traje jedan sat. - The rehearsal for the performance lasts one hour.

In Croatian, you use the accusative case without any preposition to show how long something lasts (duration of time). Since the rehearsal lasts for an hour, jedan sat is put directly into the accusative to express this duration.

If jedan sat is in the accusative case, why does it look exactly like the dictionary form?

Good catch! Sat is a masculine noun. In Croatian, masculine nouns that represent inanimate objects (things, not living beings) have the exact same form in the accusative case as they do in the nominative case. So, sat stays sat, and the number jedan also stays jedan.

Why is nastup also in the accusative case after the preposition za?

The preposition za takes the accusative case when it means for a specific purpose, event, or recipient. Here, the rehearsal is for the performance, so nastup goes into the accusative. Just like sat, it is an inanimate masculine noun, so its accusative form is identical to its nominative form.

Can sat mean something other than hour?

Yes! Depending on the context, sat can mean hour, clock, watch, or even a school lesson. Here, because it is used with the verb traje (lasts) to describe a duration of time, it clearly means hour.