Questions & Answers about Hvað finnur þú? Ekkert.
Why is "nothing" translated as ekkert here instead of enginn?
Is ekkert in the nominative or accusative case in this answer?
It acts as the accusative here. Even though it is a one-word answer, it stands in for the direct object of the implied sentence "I find nothing" (Ég finn ekkert). The verb finna (to find) requires its object to be in the accusative case. Luckily, for the neuter word ekkert, the nominative and accusative forms are exactly the same!
Why does the verb finnur come before the subject þú?
This is because of Iceland's strict verb-second word order. In a question that starts with a question word like hvað (what), that question word takes up the first slot. The verb finnur must come immediately after it in the second slot, pushing the subject þú to the third spot.