Questions & Answers about Er testet das Licht, bevor ich das Kostüm anziehe.
Why does the verb anziehe go at the very end of the sentence?
The word bevor (before) is a subordinating conjunction. These types of connecting words always kick the conjugated verb to the end of their clause.
Wait, anziehen (to put on) is a separable verb. Why isn't it separated into ziehe ... an here?
You're right that it normally separates! But when a subordinating conjunction like bevor pushes a separable verb to the end of the sentence, the two parts stick together. Instead of ich ziehe das Kostüm an, it becomes bevor ich das Kostüm anziehe.
Do I always need a comma before bevor?
Yes. In German, subordinate clauses (sentences that can't stand alone and start with words like bevor, dass, or weil) must be separated from the main sentence by a comma.
Can I just use vor instead of bevor here?
No, because they have different grammatical jobs. Bevor connects two whole clauses that have their own verbs, just like in this sentence. Vor is a preposition that goes directly in front of a noun, like in the phrase vor dem Test (before the test).