when.while-as-的区别用法

1、精选优质文档-倾情为你奉上精选优质文档-倾情为你奉上专心-专注-专业专心-专注-专业精选优质文档-倾情为你奉上专心-专注-专业when, while和as的用法一when，while，as在时间状语从句中的区别：三者均可表示“当的时候”，如果主句表示的是短暂的动作，而从句表示的是一段时间，三者可通用。如：I met Kang Li aswhenwhile I was walking along the street当我沿街散步时碰见了康丽。when可以和延续性动词连用，也可以和短暂性动词连用；而while和as只能和延续性动词连用。 如： It was snowing when we got

2、to the airport当我们到达机场时，天正下着雪。（不能用while） as强调主句与从句表示的动作同时发生，as常表示“随着”；“一边，一边；while强调主句表示的动作持续于while所指的整个时间内；when可指主、从句所述动作同时或先后发生。如：As the time went on，the weather got worse（as表示“随着”之意） He sang as he went along他边走边唱。Please write while I read我读的时候，请写下来。When he reached home，he had a little rest回到家后，他休息

3、了一会儿。when用于表示“一就”的句型中（指过去的事情）。 somebody had hardly（scarcely） done whenHardly Scarcely had somebody done when I had hardly scarcely closed my eyes when someone knocked at the doorHardly Scarcely had I closed my eyes when someone knocked at the door我刚一闭上眼，就有人在敲门了。 二.when, while和as都可引导让步状语从句： when引导让步状

4、语从句，意为“尽管，虽然”相当于though或although:They stopped trying when they might have succeeded next time. while引导让步状语从句，相当于although ，是较为正式的书面语:While I am willing to go, I would like it better that you went.as引导让步状语从句必须倒装，从句中的表语，状语或动词原形置于句首，若表语为名词，前置时省略冠词。 Child as he is, he knows a lot.Much as I like it, I will

5、 not buy it, for its too expensive.Try as he might, he couldnt find a job.三.when和while可用作并列连词:when作并列连词，意为“突然，正在那个时候”常运用于以下句型中：Somebody be about to dowhenSomebody be on the point of doingwhenSomebody be doing whenSomebody had donewhenWe were having a meeting when someone broke in.We were about to se

6、t off on our way, when it suddenly began to rain. 作并列连词，意为“而，却”，表示对比。He likes pop music, while I am fond of music.四.when和as用于原因状语从句中:when=since, now that “既然”Why do you want a new job when youve got such a good one already?意为“因为”，指说话双方都知道的原因。As he was not ready in time, we went without him.组题练习：1. S

7、uccess came _ she began to play leading parts in radio plays.A. While B. as C. when D. if 2. The atmosphere gets thinner and thinner _ the height increases. A. When B. as C. while D. since 3. I was just about to go to sleep_ there was a loud knock on the door. A. While B. when C. as D. since4. They

8、were surprised that a child should work out the problem_ they themselves couldnt.A. When B. where C. until D. while 5. We were swimming in the lake_ suddenly the storm started.A. When B. while C. until D. before 6. I do every single bit of housework_ my husband Bob just does the dishes now and then.

9、 (04高考广西卷)A. Since B. while C. when D. as 7. _ I accept that he is not perfect, I do actually like the person.(04高考江苏卷)A. While B. Since C. Before D. Unless8. Jasmine was holidaying with her family in a wildlife park_ she was bitten on the leg by a lion.(04高考上海卷) A. When B. while C. since D. once 9.

10、 _modeling business is by no means easy to get into, the good model will always be in demand.(o4高考浙江卷) A. While B. Since C. As D. If 10. All gases and most liquids and solids expand _ heated. A. as B. while C. before D. when11. We have only three books_ we need five. A. as if B. if C. when D. even t

11、hough 12.How can we explain it to you_? A. while you are listening B. unless you will listen C. as you wont listen D. when you wont listen13._ I had to work to support my family.A. When I was a little child B. While I was a little child C. As I was a little child D. Before I was a little child14._,

12、helicopters flew to the burning building. A. While the firefighters were trying to control the fire B. As the firefighters were trying to control the fire C. As soon as the firefighters were trying to control the fire D. After the firefighters had controlled the fire15. The husband was looking after

13、 the baby_. A. after his wife cooked in the kitchen B. as his wife was cooking in the kitchen C. when his wife was cooking in the kitchen D. while his wife was cooking in the kitchen16. Look at the sun. It is shining._ its sunny, lets go for a walk. A. as B. when C. if D. as soon as17. The sad mother sat on the roadside，shouting_ she was crying. A. what B. when C. as D. which18. Hardly had we entered the room _ it began to rain. A. while B. as C. then D. when19. _, he does get annoyed with her sometimes.(04). A. Although mu