be‧fore S1 W1 / bɪfɔ $ -fɔr / 连词 #

1 earlier than a particular event or action 反义词 after :

Say goodbye before you go.

I saw her a few days before she died.

2 so that something does not or cannot happen :

Put that money somewhere safe before it gets stolen.

That dog ought to be destroyed before it attacks any more children.

Before I could say anything more, Holmes had rushed off towards the station.

3 used to say that something happens after a period of time :

It was several minutes before we realised what was happening.

It will be a while before we know the results.

4 used to say that something must happen in order for something else to be possible :

You have to pass a test before you can get a licence.

5 spoken used to warn someone that something bad will happen to them if they do not do something :

Get out before I call the police!

6 used to emphasize that someone does not want to do something :

She would die before she would admit she was wrong.

Grammar

In a clause beginning with before that refers to the future, use the present tense or present perfect, not ‘will’ :

I want to get home before it rains (NOT before it will rain).

because S1 W1 preposition #

because of somebody/something used to say who or what causes something to happen or is the reason for something :
He had to retire because of ill health. We spent three hours waiting in the rain because of you!

Register In written English, people often prefer to use the expressions due to something, owing to something, or as a result of something, which sound more formal than because of something :
Many businesses fail due to cash-flow problems.

before S1 W1 adverb #

1 at an earlier time :
Haven’t I met you before somewhere? Never before had he seen so many people starving. She looked just the same as before. 2 the day/week/month etc before the previous day, week, month etc OPP after :
She was in Paris last week and in Rome the week before. 3 old use ahead of someone or something else :
The king’s herald walked before.