This is the 34th most frequent Vietnamese word.
trước
"Trước" means "before" or "in front of" in English.
In this sentence, 'trước' is used as a preposition indicating a temporal relationship ('before').
Tôi đã đến đây trước anh ấy.
I arrived here before him.
Here, 'trước' is part of the conjunction 'trước khi', used to indicate a preceding condition or action ('before').
Hãy làm việc này trước khi bạn rời đi.
Please do this before you leave.
In this context, 'trước' is a preposition indicating a spatial relationship ('in front of').