while的第一种用法是，可用作名词和连词，译为一段时间，一会儿，当……时候，虽然，尽管。while的第二种用法是用作连词时，意为当……时候，和……同时时，引导时间状语从句。

While例句

It will take a while for the drug to work out of your system.

这药得需要一段时间才能排出你的体外。

I'll be back in a little while.

我一会儿就回来。

You'll water the plants while I'm away, won't you?

我外出的时候请你给花草浇浇水，行不行？

Her parents died while she was still at school.

她还在读书时父母就去世了。

He'll do the job if you make it worth his while.

你要是给他的报酬丰厚，他会做这份工作的。

While的用法归纳

一、while意为“当……时候”,指一段时间,不能用来表示一个时间点。

Whilethe discussion was still going on，George came in.当讨论还在进行时,乔治走了进来。

二、while意为“而;然而”,表示转折。

There're plenty of rain in the southeast,whilethere's little in the northeast.东南部雨量充足,而西北部则很少下雨。

三、while意为“虽然;尽管”,表示让步。

WhileI admit his good points，I can see his shortcomings.尽管我承认他的优点,但我还是能看到他的缺点。

四、while意为“只要”,表示条件。

We can surely overcome these difficultieswhilewe are closely united.只要我们紧密地团结一致,一定能克服这些困难。

五、while从句中的省略。

当while从句中的主语与主句的主语一致,且含有be的某种形式时,从句中的主语连同be可同时省略。

Whilelistening to the radio，she fell asleep.她在听收音机时睡着了。

Whilein London，he studied music and painting.在伦敦时,他学习音乐和绘画。

六、while可用作名词,意为“一会儿;一段时间”。

作名词用时,主要用于短语中: after awhile“过了一会儿”; all thewhile“一直,始终”; a short/littlewhileago “刚才”; once in awhile“偶尔,间或”; wait/rest(for) awhile“等/休息一会儿”。

I haven't seen her for a longwhile.我好久没有看见她了。

Where have you been all thiswhile?这一阵子你到哪去了?

He usually goes to work by bike，but once in awhilehe goes by bus.他通常骑自行车上班,但偶尔也乘公共汽车。

I looked everywhere for the letter，but it was in my pocket all thewhile.我到处找那封信,却不知它一直在我口袋里。

七、while与when以及as之间的区别。

1.当从句中的谓语动词是持续性的动作时,我们可以用while，when或as。

While/ When/As I was walking down the street，I noticed a police car in front of the bank.我顺着马路往前走时,发现银行门前停着一辆警车。

2.当从句中的谓语动词表示瞬间动作时,不可用while。

He was on the point of leaving when someone knocked at the door.他正要走,这时有人敲门。

3.如果谈论两个长动作,最常用的是while。

WhileJohn was sitting biting his nails，I was working out a plan to get us home.约翰坐在那里咬指甲时,我想出了一个回家的办法。

不过，as是可以用来说明两种正在发展或变化的情况的,这时as引导一个持续性的动作,主句中的动作与之同时进行。

As we talked on，he got more and more excited.我们继续往下谈的时候,他越来越兴奋。

4.如果表示两个短动作或事件同时发生,最常用的是as或just as,也可用when。

Just as he caught the ball，there was a tearing sound.当他抓住球的时候,有一种撕裂的声音。

I thought of it just when you opened your mouth.就在你要说话的时候,我也想到了。