Questions & Answers about Brauchen wir einen Pass?
Why is it einen Pass and not just ein Pass?
Pass (passport) is a masculine noun. In this sentence, it is the direct object of the verb brauchen (to need) — it is the thing being needed. This puts it in the accusative case. For masculine nouns in the accusative, the word for "a" changes from ein to einen.
How do you form a yes/no question like this in German?
You just move the verb to the front! A regular statement would be Wir brauchen einen Pass (We need a passport). To turn it into a yes/no question, you simply swap the subject (wir) and the verb (brauchen) to make Brauchen wir einen Pass?
Why is there no German word for "Do" in this sentence?
German doesn't use helper words like "do" or "does" to ask questions. While in English we say "Do we need...?", German simply asks "Need we...?" by putting the main verb first.
What if we needed something feminine or neuter instead? Would we still use einen?
No, the -en ending on einen is only for masculine nouns in the accusative case. If you needed a bag (feminine: die Tasche), you would ask Brauchen wir eine Tasche?. If you needed a book (neuter: das Buch), it would be Brauchen wir ein Buch?.