Learn Croatian: Zašto rano ideš na posao? - Why are you going to work early?

In Croatian, the subject pronoun ti (you) is usually dropped because the verb ending already tells us who is acting. The verb ići (to go) takes the form ideš to mean 'you are going'.

Why do we use na instead of u for going to work?

When talking about destinations with verbs of motion, we use na for events, activities, and public spaces. Since work (posao) is considered an activity or concept rather than just a physical building, you go na posao. The preposition u is mostly saved for physically walking into enclosed structures.

Is posao in the accusative case here since it is a destination?

Yes, it is! When you are going somewhere, the destination takes the accusative case. It looks exactly like the dictionary form here because posao is a masculine, inanimate noun (a thing, not a living being). For these nouns, the accusative and nominative forms are identical.

Can I change the word order to 'Zašto ideš rano na posao'?

Absolutely. Croatian word order is very flexible. Putting the adverb rano (early) right before the verb ideš puts a bit more focus on the 'early' part, but both versions mean the exact same thing and sound natural.