高三课本第十五单元，INTER GATING SKILLS 和 WORKBOOK READING部分有如下的句子：

⒈The shop was successful，but it was about sixty years before people started to buy jeans for fashion as well as for work.

⒉However，it probably will not be long before the other mountainous areas of China such as Sichuan，Xinjiang and Yunnan are developed，and as more facilities become available，prices will almost certainly fall.

其中涉及到before的用法，下面就其用法进行总结。

一、可以用作介词

⒈)指时间上早于，在……之前，如：

She has lived here since before the war.

她从战前就一直在这儿住。

⒉)指位置在前面，如：

We knelt down before Grandma's grave.

我们在奶奶的墓前跪下。

⒊)指顺序或排列在之前，如：

Your name comes before mine on the list.

名单上你的名字在我之前。

⒋)在某人面前，如：

She said it before the witness.

他是当着证人的面说的。

二、作为连词

其基本含义是“在……之前”，又可以根据不同语境灵活翻译成“才”、“还没来得及就……”、“趁……”、“就”等。具体用法如下：

⒈)与情态动词can/could连用

这时候从句虽为肯定形式，根据汉语表达习惯译成“还没来得及就”，如：

Before I could get in a word，he had measured me.

我还没来得及插话他就为我量好了尺寸。

Before she could move，she heard a loud noise，which grew to a terribl eroar.

她还没来得及迈步，就听见一声巨响，接着就是可怕的隆隆轰鸣。

⒉)用于肯定句中强调主句所表达的时间，距离长，或花费的精力大，译成“才”

We had sailed four days and four nights before we saw lands.

我们航行了四天四夜才看到陆地。

We waited a long time before the train arrived.

我们等了很长时间火车才到。

⒊)用于否定句中，强调主句所表达的时间，距离短，或花费的精力小，译成“不到……就”如：

We hadn't run a mile before he felt tired.

我们跑了还不到一英里他就累了。

⒋)主句含有hardly，scarcely等半否定副词时可以译为“刚……就”

这时候主句应用过去完成时态，从句用过去时，还可以用when替代before如：

We had scarcely reached the school before/when the bell rang.

我们刚到学校铃声就响了。

⒌)有时还有“宁愿”的意思

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

⒍)用于It+be/take+时间段+before句型

在这一句型中又可以根据主从句的时态分成两种情况。

若主句是一般时将来时态，从句是一般现在时.若主句是肯定句意思是“要过多长时间才”；若主句是否定形式翻译成“用不了多久就”。

It will be two weeks before everything returns to normal.

两周之后一切才能恢复正常。

It will be many years before the situation improves.

这种状况或许要过许多年才能得以改善。

It won't be long before we meet again.用不了多久我们就会再见面的。

这时若主句是一般过去时从句也是一般过去时。若主句是肯定句翻译成“多长时间之后才”，若主句是否定形式翻译成“没过多久就”。如：

It was some time before I realized the truth.

过了很长一段时间我才了解到真相。

It wasn't long before she became a brave solider.

没过多久她就成了一名勇敢的战士。

After that it still took seven years before they got married.

他们又过了七年才结婚。

注意：当主句的谓语动词为延续性动词时，before与until有时可以互换。It was an hour before/until the police arrived.

■巩固练习

⒈(2004天津)It was evening ________ we reached the little town of Winchester.

Athat   B.until   C.since   D.before

2.(2004全国)Several weeks had gone by ________ realized the painting was missing.

A.as   B.before   C.since   D.when

3.(2005广东)The America Civil War lasted four years ______ the North won in the end.

A.after   B.before   C.when   D.then

4.(2005山东)It was some time _______ we realized the truth.

A.when   B.until   C.since   D.before

5.(2006四川)-Why didn't you tell him about the meeting？

-He rushed out of the classroom _______ I could say a word.

A.before   B.until   C.when   D.after

6.(2006福建)-How long do you think it will be __ china sends a manned spaceship to the moon？

-Perhaps two or three years.

Awhen   B.until   C.that   D.before

参考答案：DBBDAD