before用法

before的用法

before的用法

1 作介词

A．指时间．在……以前． e.g. It began to rain before midnight .

B. 指位置．在……面前． e.g. They knelt before the king .

C. 指顺序或排列在前面． e.g. You name comes before mine on the list .

2 作连词

A．在……之前． e.g. Did she leave a message before she went ?

B．用于It + be +时间段+ before ：在……之后才……

e.g. It willl be five years before I come back .

3 常于情态动词can / could 连用：还没来得及……就……

e.g. Before I could say a word , she had rushed out of the room

掌握before热点用法

1. prep. 在......以前，强调时间

He came to see me the day before yesterday. 他前天来看我了。

2. prep. 在......前面，当着......的面，向......，强调地点

She has to appear before the court. 她必须出庭受审。

3. prep. 在......之前，先于，强调次序

Those with babies can get on the bus before others. 带小孩的人可以先上汽车。

4. prep. 与其......（宁愿）

I'd shoot myself before I apologized to him! 我宁死也不向他道歉!

5. adv. 以前，强调时间

We've seen that film before. 我们以前看过那场电影。6. adv. 在前面，向前，强调位置

Don't run before and after. 别跑前跑后。

7. conj. 在......前，强调时间

before的含义比较灵活，实际翻译时应结合具体情况机动处理。

1. 趁......

You should do it before it is too late. 趁现在还不算太晚，你应该赶快做它。

2. 尚未来得及

Before she could move, she heard a loud noise, which grew to a terrible roar. 她还没有来得及动弹，就听见有很响的声音，接着就成了可怕的隆隆轰鸣声。

Before they reached the house, a new great wave came,

sweeping down trees, and sweeping them down too. 他们还没到屋子，又一个巨浪打来，冲倒了树，也冲倒了他们。

3. 要......先......

You should be a pupil before you become a teacher. 要当老师，先作学生。

二、掌握热点句型用法

It was not long before...（过去）没过多久就......

It was not long before he returned to Beijing. 不久他就回到北京。

需要特别注意，该句型可以进行创新，可将否定句改为肯定句（It was long before...过了很久才......）或将一般过去时改为一般将来时（It will not be long before...要不了多久就......；It will be long before...要过很久才......）。before在这些句型中均引导时间状语从句，long这个抽象的时间也可改为years, weeks, days等具体表时间的词。

It was long before he married Wei Fang. 过了很久他才娶魏芳。It will be long before he goes abroad. 要过很久他才出国。

Will it be years before he goes to school? 要过好几年他才能上学吗？

高考题例：

It ________ long before we ________ the result of the experiment.

A. will not be...will know

B. is...will know

C. will not be...know

D. is...know

【析】正确答案为C。该句面意思为：在我们知道实验结果之前不会过很长一段时间，也就是不会过很长一段时间我们就会知道实验结果。应使用It was not long before的创新句型It will not be long before，before引导时间状语从句时，从句应用一般现在时代替一般将来时。

Scientists say it may be five or six years ________ it is possible to test this medicine on human patients.

A. since

B. after

C. before

D. when

【析】正确答案为C。该句型也是It was not long before的创新句型。

when与befor的区别

本文结合典型例题来归纳一下before的特殊用法。

before作为连词时的基本意义是“在……之前”，用于表示时间或顺序。如：Turn the light off before you sleep. (睡前先把灯熄掉。) Think before you speak. (说话之前，应先想清楚。) 但在不同的语境中before有不同的意义：

1．before表示“不等……就……”、“尚未……就……”

例1：—Why didn’t you tell him about the meeting？(2006年四川)

—He rushed out of the room I could say a