Breakdown of Je li to auto koji su jučer ukrali?
biti
to be (sam, si, je)
to
that
li
question particle
auto
car (short form)
Questions & Answers about Je li to auto koji su jučer ukrali?
Why is the relative pronoun koji used here, and not kojeg?
Koji refers back to auto, which is the direct object (accusative case) of the verb ukrali (stole). Because auto is a masculine inanimate noun (an object, not a living being), its accusative form is exactly the same as its nominative form: koji. If the noun were animate, you would use kojeg instead.
Wait, doesn't auto end in -o? Why are we using the masculine pronoun koji instead of the neuter koje?
It is a very common exception! The word auto is short for automobil, which ends in a consonant and is clearly masculine. Because of this, auto behaves as a masculine noun despite its -o ending. That is why it pairs with the masculine relative pronoun koji.
Who exactly is the subject of su ukrali (stole) here?
The subject is a generic 'they' (oni), which is dropped here because the verb forms (su and ukrali) already tell us it is third-person plural. In Croatian, using a generic 'they' is a standard way to describe an event like a theft when the exact perpetrators are unknown.
Why does the sentence start with Je li instead of a question word like Da li je?