Basic questions can be formed by placing the verb in first position instead of second: Sie isst. (she's eating) Isst sie? (Is she eating?) In a more complicated sentence, the rule is still the same, the conjugated verb (whether aux verb or not) goes first: Er möchte nach Hause fahren. (He wants to drive home) Möchte er nach Hause fahren? (Does he want to drive home?) The main exception to this is if you use a question word, (wann, wer, wie, warum, wo) In that case, the question word goes first, followed by the verb, followed by the subject, then any other phrases: Warum schickte sie letzte Woche solch ein großes Paket nach Irland? (Why did she send such a large parcel to Ireland last week?)