初二while的用法归纳分点回答

　　另外while还有别的用法：

　　一、while引导状语从句,有以下两种含义：

　　1．表示某个动作正在进行的同时,另一动作也在进行之中,这时主从句都用进行时态,有对同类的两个动作进行对比的意味.如：

　　While I was playing the piano,she was dancing．我在弹钢琴,她在跳舞.

　　While Jim is picking apples,Kate is carrying apples to the truck．吉姆正在摘苹果,凯特正在把苹果搬到卡车上去.

　　2．表示某个动作正在进行时,又发生了另一动作（该动作用一般过去时）.如：

　　While I was reading,I fell asleep．我读着读着就睡着了.

　　While we were swimming in the river,we saw a fish jump out of the water．我们正在河中游泳时,看见一条鱼跃出了水面.

　　二、短语用法

　　1．只要（＝as long as）

　　There will be life while there is water and air．只要有空气和水,就会有生命.

　　2．而；然而〔表示对比〕

　　He is a driver while I'm a teacher．他是司机,而我是老师.

　　3．虽然（＝although）；尽管〔表示让步〕

　　While I see what you say,I can't agree with you．虽然我能理解你说的话,但是我不能同意你.

　　4．用作名词,表示“一会儿或一段时间”,常与a,the或this等连用.如：

　　Just wait a while and then I will help you.等一下,我会来帮你的.

　　Where have you been all this while?这一阵子你一直都在哪儿?

　　三、引导时间状语从句

　　while所引导的时间状语从句中的谓语动词只能是延续性动词。

　　例如：I met with an old friend of mine while(when) I was walking along the street.

　　while 引导状语从句时,应注意以下几点:

　　1.while 引导的时间状语从句既可放在句首,也可放在句末;而 while 引导的让步状语从句一般放在句首,不放在句末.另外,也可以从意义上加以区分.

　　例如:While he was tired, he went on working.(虽然他累了,但他还是继续工作.)(while 引导让步状语从句)While he was tired, he would have a rest.(他累了就休息一会儿.)(while 引导时间状语从句)

　　2. while 引导让步状语从句时,如果从句的主语和主句的主语相同,那么从句的主语和谓语动词 be 都可以省略.

　　例如:While he was ill, he went there. (= While ill, he went there.)(虽然他有病,但他还是去那里了.)

　　3. while 和 when 都可以引导时间状语从句,但应注意: while 引导的时间状语从句中的谓语动词必须是延续性的动词;而 when 引导的时间状语从句中的谓语动词既可以是延续性动词,也可以是非延续性动词.当时间状语从句中的谓语动词是延续性动词时, while 和 when 可以互相替换.

　　例如:While we were talking, the teacher came in.(我们正在谈话时,老师进来了.)