Breakdown of Zašto ste se jučer ljutili?
biti
to be (sam, si, je)
zašto
why
jučer
yesterday
ljutiti se
to be angry
Questions & Answers about Zašto ste se jučer ljutili?
Why is se placed right after ste instead of next to the main verb ljutili?
Both ste (are) and se (oneself) are clitics, which are short words without their own stress. In Croatian, clitics must cluster together in the second position of the sentence. Since the question word Zašto takes the first position, the clitic cluster ste se must come immediately after it.
Could I change the order and say Zašto se ste jučer ljutili?
No, the order of clitics within that second-position cluster is strictly fixed. When you have a verb clitic like ste and the reflexive clitic se, the verb clitic must always come first.
Why do we need the reflexive word se here at all? The English translation doesn't say 'angry yourself'.
In Croatian, being angry is expressed with the reflexive verb ljutiti se, which acts a bit like saying 'to anger oneself'. If you drop the se, the verb ljutiti means to make someone else angry!
Why does the main verb ljutili end in -i?
This is the past tense action word, and its ending changes to match the subject. The -i ending tells us this is plural (or the formal, polite 'you') and refers to men or a mixed group. If you were formally addressing one woman, or a group of only women, it would be ljutile.