while的用法

由高考题看while的用法

[常见错误]

误①：While I came in, he was reading a book.

误②：She took a bath while preparing a meal.

误③：She drinks black coffee when I prefer it with cream.

误④：While he understands your idea, but he doesn't agree with you.

[主要用法]

1. 用作从属连词，意思是“当……时；和……同时”，引导时间状语从句。注意该状语从句的谓语动词必须是延续性动词，不能是终止性动词，如果是终止性动词，酌情用when或as。

They phoned while you were out. 你不在家时他们打来了电话。（be out为延续性动词）When I came in, he was reading a book. 我进来时，他正在看一本书。（come 为终止性动词）（参见“误①”）

2. 如果从句的主语与主句的主语为同一人且从句的谓语含有系动词be时，可省略从句的主语及系动词be；如果从句的主语与主句的主语不是同一人，则不可省略。

The child watched TV while (he was) eating. 这个男孩边吃边看电视。

She took a bath while I was preparing a meal. 我准备饭菜的时候，她在洗澡。（参见“误②”）

3. 用作并列连词，意思是“但；却；然而”，表示对比或与前面的情况相反，注意when和as不能表示这一含义。

She drinks black coffee while I prefer it with cream. 她喜欢喝清咖啡而我喜欢加奶油的。（参见“误③”）

I earn only 100 dollars a month, while you earn 400 dollars. 我一个月只赚一百美元，你却赚四百美元。

4. 用作从属连词，表示让步，意思是“虽然”，其意义相当于although，主要用于书面语中。注意主句的前面不可有but等连接词。

While he understands your idea, he doesn't agree with you. 虽然他了解你的想法，但他还是不赞同你。（参见“误④”）

5. while作名词时，意思是“一点时间；一会儿”，表示泛指时常与a连用；表示特指时可与the, this, that连用。常用的短语有：after a while过了一会儿；all the while一直；in a while 不久；once in a while偶尔等。

It took her quite a while to find a hotel. 她花了很长时间才找到一家旅馆。

Where have you been all this while? 这阵子你一直在哪儿？