Learn German: Wir singen nicht, bevor das Mikrofon funktioniert. - We do not sing before the microphone works.

The word bevor (before) is a subordinating conjunction. This means it introduces a dependent clause and forces the conjugated verb (funktioniert) to the very end of that part of the sentence.

Is bevor used exactly like vor? Don't they both mean 'before'?

They both translate to 'before', but they do different jobs. You use bevor to connect an entire clause that has its own verb (like 'before the microphone works'). You use vor as a preposition directly before a noun, like vor dem Konzert (before the concert).

Why do we need a comma before bevor?

In German punctuation, you must always separate a main clause (Wir singen nicht) from a subordinate clause (the part starting with bevor) with a comma. Unlike in English, this comma is never optional.

Could we flip the sentence around and start with bevor?

Yes! You could say: Bevor das Mikrofon funktioniert, singen wir nicht. Notice that the entire bevor clause acts as the first block of information. Because the verb must be in the second position in a main clause, the verb singen comes immediately after the comma.