状语从句中的when, while和as的用法
一．when，while，as在时间状语从句中的区别：
①三者均可表示“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 as／when／while I was walking along the street．
当我沿街散步时碰见了康丽。
②when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 to the airport．当我们到达机场时，天正下着雪。
（不能用while）
③as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，他休息了一会儿。
④when用于表示“一……就……”的句型中（指过去的事情）。
somebody had hardly（＝scarcely）done …when．．．
＝Hardly ／Scarcely had somebody done …when．．．
①I had hardly ／scarcely closed my eyes when someone knocked at the door．
＝Hardly ／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：
①when引导让步状语从句，意为“尽管，虽然”相当于though或although: They stopped trying when they might have succeeded next time.
②while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.
③as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 not buy it, for it’s too expensive.
Try as he might, he could n’t find a job.
三.when和while可用作并列连词:
①when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 do…when…
Somebody be on the point of doing…when…
Somebody be doing… when…
Somebody had done…when…
We were having a meeting when someone broke in.
We were about to set off on our way, when it suddenly began to rain.
②while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:
①when=since, now that… “既然”
Why do you want a new job when you’ve got such a good one already?
②as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. Success 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. since
4. They were surprised that a child should work out the problem_____ they themselves
couldn’t.
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.
A. Since
B. while
C. when
D. as
7. _____ I accept that he is not perfect, I do actually like the person.
A. While
B. Since
C. Before
D. Unless
8. Jasmine was holidaying with her family in a wildlife park__ she was bitten on the leg by a lion.
A. When
B. while
C. since
D. once
9. _____modeling business is by no means easy to get into, the good model will always be in demand.
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. when
11. We have only three books______ we need five.
A. as if
B. if
C. when
D. even though
12.How can we explain it to you_____?
A. while you are listening
B. unless you will listen
C. a s you won’t listen
D. when you won’t listen
13._______ 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 child
14._____________, 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 fire
15. The husband was looking after 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 kitchen
16. Look at the sun. It is shining._______ it’s sunny, let’s go for a walk.
A. as
B. when
C. if
D. as soon as
17. The sad mother sat on the roadside，shouting_______ she was crying.
A. what
B. when
C. as
D. which
18. Hardly had we entered the room ______ it began to rain.
A. while
B. as
C. then
D. when
19. ___________, he does get annoyed with her sometimes.
A. Although much he likes her
B. Much although he likes her
C. As he likes her much
D. Much as he likes her
20.______ years go by，China is getting stronger and richer
. A. When B. As C. While D. Since
Keys:1---10 CBBDA/ BAAAD 11-----20 CDAAD/ ACDDB
Summary 3 Past Co nti nuous Tense 过去进行时总结 I. Defin itio n 时态含义 表示过去某一时刻或过去一段时间内正在进行的动作。 II. Time words 时间标志词 1. then, at that time, this time yesterday, at 6 o ' clock yesterday ... 2. when/ while/ (just) as 引导的时间状语从句 III. Structure 动词结构 was/ were + doing ? Whe n/ while/ (just) as 引导的时间状语从句在过去进行时态中的用法区别 1. when既可以和短暂性动词连用，也可以和连续性动词连用, 句中一般翻译为“当...... 时候” / “就在那时”。 a. Some one kno cked at the door whenI was hav ing breakfast. b. I was tak ing a bath whenthe teleph one rang. 2. while只可以和连续性动词连用 句中一般翻译成“当...... 时候”(=wheri) / “然而”(强调前后两个动作同时进行) a. He cut himself while he was shaving. b. My wife was cooking the dinner while I was working in the garden. 3. (just) as 更强调“随着”，所引导的从句动作一般与主句动作伴随着发生。 a. Just as I was ope ning the front door, the teleph one rang. b. The children were singing as they went home.
when 和while的用法区别 两者的区别如下： ①when是at or during the time that, 既指时间点，也可指一段时间； while是during the time that，只指一段时间，因此when引导的时间状语从句中的动词可以是终止性动词，也可以是延续性动词，而while从句中的动词必须是延续性动词。 ②when 说明从句的动作和主句的动作可以是同时，也可以是先后发生；while 则强调主句的动作在从句动作的发生的过程中或主从句两个动作同时发生。 ③由when引导的时间状语从句，主句用过去进行时，从句应用一般过去时；如果从句和主句的动作同时发生，两句都用过去进行时的时候，多用while引导，如： a. When the teacher came in, we were talking. 当此句改变主从句的位置时，则为： While we were talking, the teacher came in. b. They were singing while we were dancing. ④when和while 还可作并列连词。when表示“在那时”；while表示“而，却”，表对照关系。如： a. The children were running to move the bag of rice when they heard the sound of a motor bike. 孩子们正要跑过去搬开那袋米，这时他们听到了摩托车的声音。 b. He is strong while his brother is weak. 他长得很结实，而他弟弟却很瘦弱。 一。引导时间状语从句时，WHILE连接的是时间段，而WHEN连接的多是时间点 例如What does your father do while your mother is cooking? What does your mother do when you come back? 二，WHILE可以连接两个并列的句子，而WHEN不可以 例如I was trying my best to finish my work while my sister was whtching TV 三，WHEN是特殊疑问词，对时间进行提问，WHILE不是。 例如，When were you bron? 续性动词和短暂性动词 英语中的动词，是学习中的重点，又是难点。英语中的动词有多种分类法。根据其有无含义，动词可分为实义动词和助动词；根据动词所表示的是动作还是状态，可以分为行为动词和状态动词；根据动词所表示的动作能否延缓，分为延续性动词和终止性动词。 可以表示持续的行为或状态的动词，叫做“延续性动词”，也叫“持续性动词”，如：be, keep, have, like, study, live, etc. 有的表示短暂、瞬间性的动词，叫做“终止性动词”，也可叫“短暂性动词”，或“瞬间性动词”，如die, join, leave, become, return, reach, etc.
一、从句是如何出题的？ 1. 时态 2. 考连接词 3. 考语言顺序 二、学好从句的两个基本条件 1. 时态 2. 从句的三个必须:①必须是句子；②必须有连接词；③必须是陈述句 三、状语从句、宾语从句、定语从句重点 1.如何判断何种从句 2. 从句的时态 3. 从句的连接词与扩展 4. 经典单选、从句与选词、长句子分析 四、如何判断三种从句 1. 状语从句无先行词 2. 宾语(表语)从句无先行词有动词或词组 3. 定语从句先行词多为名词或代词 一、When引导的定语从句与时间状语从句的区分 1. when的译法不同。在时间状语中，when 翻译成“当……的时候” I want to be a teacher when I grow up. 当我长大的时候，我要做一名老师。在定语从句中，when不翻译。I won't forget the day when he says he loves me. 我不会忘记他说爱我的那一天。 2. 在时间状语中，when从句前面或后面是句子；定语从句中，when 从句不能位于句首，且通常when前为表示时间的名词day、year等。 3. when在从句的作用不同。在时间状语从句中，when是连词，只起连接主句和从句的作用，不做从句的任何成分。不过when引导的时间状语从句修饰主句的谓语，做主句的时间状语。 在定语从句中，when是关系副词，在从句中代替先行词做从句的时间状语，修饰从句的谓语。 例1 I will always remember the days when I lived with my
grandparents in the country. 例2 I always remember the days in the country when I see the photo of my grandparents. 点评：例1意为“我会永远记得跟我祖父母一起住在乡下的那些日子”，其中when 引导的是一个定语从句, 修饰the days, when在从句中作时间状语。例2意为“当我看到祖父母的照片时，总是会想起在乡下的那些日子”，其中when 引导的从句并不修饰前面的名词the country，因此可判定为时间状语从句。 例1中的when可用in which替代，即从句可改为...in which I lived with my grandparents in the country. 例2中从句前有名词，但根据句意可 知并不是从句所修饰的对象，也不能用“介词+ which”来替代。 二、判断关系代词与关系副词 方法一：用关系代词，还是关系副词完全取决于从句中的谓语动词。及物动词后面无宾语，就必须要求用关系代词；而不及物动词则要求用关系副词。例如： This is the mountain village where I stayed last year. 这是我去年呆过的山村。 I'll never forget the days when I worked together with you. 我永远不会忘记与你共事的日子。 判断改错： 1. This is the mountain village where I visited last year. 2. I will never forget the days when I spent in the countryside. 3. This is the mountain village （which）I visited last year.
when和while用法区别专项练习 讲解三例句： 1. The girls are dancing while the boys are singing. 2. Kangkang’s mother is cooking when he gets home. 3. When/While Kangkang’s mother is cooking, he gets home. 一、用when或者while填空 Margo was talking on the phone, her sister walked in. we visited the school, the children were playing games. · Sarah was at the barber’s, I was going to class. I saw Carlos, he was wearing a green shirt. Allen was cleaning his room, the phone rang. Rita bought her new dog; it was wearing a little coat. 7. He was driving along ________ suddenly a woman appeared. 8. _____ Jake was waiting at the door, an old woman called to him. 9. He was reading a book ______suddenly the telephone rang. 10. ______ it began to rain, they were playing chess. [ 二、用所给动词适当形式填空 11. While Jake __________ (look) for customers, he _______ (see) a woman. 12. They __________ (play) football on the playground when it _____ (begin) to rain. 13. A strange box ________ (arrive) while we _________ (talk). 14. John ____________ (sleep) when someone __________ (steal) his car. 15. Father still (sleep) when I (get) up yesterday morning. 16. Grandma (cook) breakfast while I (wash) my face this morning. 17. Mother (sweep) the floor when I (leave) home. ~ 18. I (read) a history book when someone (knock ) at the door. 19. Mary and Alice are busy (do) their homework. 20. The teacher asked us (keep) the windows closed. 21. I followed it (see) where it was going. 22. The students (play) basketball on the playground from 3 to 4 yesterday afternoon. / 三、完成下面句子，词数不限 1.飞机在伦敦起飞时正在下雨。 It when the plane in London. 2.你记得汶川大地震时你在做什么吗 Do you remember what you when Wenchuan Earthquake . 3.当铃声想起的时候，我们正在操场上玩得很开心。 We on the playground when the bell . 4.当妈妈下班回家时，你在做什么 % when Mum from work 5.当我在做作业时，有人敲门。 I was doing my homework, someone
when和while的用法解析、练习题及答案（附总结表格） 一、讲解三例句: 1. The girls are dancing while the boys are singing. 2. Lucy’s mother is cooking when she gets home. 3. When/While Lucy’s mother is cooking, she gets home. 二、用when或者while填空 1.______ Margo was talking on the phone, her sister walked in. 2.______ we visited the school, the children were playing games. 3.______ Sarah was at the barber’s, I was going to class. 4.______ I saw Carlos, he was wearing a green shirt. 5.______ Allen was cleaning his room, the phone rang. 6.______ Rita bought her new dog; it was wearing a little coat. 7. He was driving along ________ suddenly a woman appeared. 8. _____ Jake was waiting at the door, an old woman called to him. 9. ______ it began to rain, they were playing chess. 10. She saw a taxi coming ______ the woman was waiting under the streetlight. 三、语法 while和when都是表示同时，到底句子中是用when还是while主要看主句和 从句中所使用 的动词是短暂性动作(瞬时动词)还是持续性动作。 1、若主句表示一个短暂性动作，而从句表示的是一个持续性动作时，用 When/While。如: He fell asleep when while he was reading. 他看书时睡着了。
WHEN与WHILE用法区别 when, while这三个词都有"当……时候"之意，但用法有所不同，使用时要特别注意。 ①when意为"在……时刻或时期"，它可兼指"时间点"与"时间段"，所引导的从句的动词既可以是终止性动词，也可是持续性动词。如： When I got home, he was having supper.我到家时，他正在吃饭。 When I was young, I liked dancing.我年轻时喜欢跳舞。 ②while只指"时间段"，不指"时间点"，从句的动词只限于持续性动词。如：While I slept, a thief broke in.在我睡觉时,盗贼闯了进来。 辨析 ①when从句与主句动作先后发生时，不能与while互换。如： When he has finished his work, he takes a short rest.每当他做完工作后，总要稍稍休息一下。(when = after) When I got to the cinema, the film had already begun.当我到电影院时，电影已经开始了。(when=before) ②when从句动词为终止性动词时，不能由while替换。如： When he came yesterday, we were playing basketball.昨天他来时，我们正在打篮球。 ③当从句的谓语是表动作的延续性动词时，when, while才有可能互相替代。如：While / When we were still laughing, the teacher came in.正当我们仍在大声嬉笑时，老师进来了。 ④当从句的谓语动词是终止性动词，而且主句的谓语动词也是终止性动词 时,when可和as通用，而且用as比用when在时间上更为紧凑，有"正当这时"的含义。如： He came just as (or when) I reached the door.我刚到门那儿，他就来了。 ⑤从句的谓语动词如表示状态时，通常用while。如： We must strike while the iron is hot.我们应该趁热打铁。 ⑥while和when都可以用作并列连词。
过去进行时过去进行时表示过去某一时刻或者某段时间正在进行或发生的动作，常和表过去的时间状语连用，如： 1. I was doing my homework at this time yesterday. 昨天的这个时候我正在做作业。 2. They were waiting for you yesterday. 他们昨天一直在等你。 3. He was cooking in the kitchen at 12 o'clock yesterday. 昨天12点，他正在厨房烧饭。 过去进行时的构成： 肯定形式：主语+was/were+V-ing 否定形式：主语+was not (wasn't)/were not (weren't)+V-ing 疑问形式：Was/Were+主语+V-ing。 基本用法： 1. 过去进行时表示过去某一段时间或某一时刻正在进行的动作。常与之连用的时间状语有，at that time/moment, (at) this time yesterday (last night/Sunday/week…), at+点钟+yesterday (last night / Sunday…)，when sb. did sth.等时间状语从句，如： 1）What were you doing at 7p.m. yesterday? 昨天晚上七点你在干什么？ 2）I first met Mary three years ago. She was working at a radio shop at the time. 我第一次遇到玛丽是在三年前，当时她在一家无线电商店工作。 3）I was cooking when she knocked at the door. 她敲门时我正在做饭。 2. when后通常用表示暂短性动词，while后通常用表示持续性动词，而while所引导的状语从句中，谓语动词常用进行时态，如： When the car exploded I was walking past it. = While I was walking past the car it exploded. 3. when用作并列连词时，主句常用进行时态，从句则用一般过去时，表示主句动作发生的过程中，另一个意想不到的动作发生了。如： I was walking in the street when someone called me. 我正在街上走时突然有人喊我。 4. when作并列连词，表示“（这时）突然”之意时，第一个并列分句用过去进行时，when引导的并列分句用一般过去时。如：
as when while 的区别和用法 as when while的用法 一、as的意思是“正当……时候”,它既可表示一个具体的时间点，也可以表示一段时间。as可表示主句和从句的动作同时发生或同时持续，即“点点重合”“线线重合”；又可表示一个动作发生在另一个动作的持续过程中，即“点线重合”， 但不能表示两个动作一前一后发生。如果主句和从句的谓语动词都表示持续性的动作，二者均可用进行时，也可以一个用进行时，一个用一般时或者都用一般时。 1、As I got on the bus，he got off. 我上车，他下车。（点点重合）两个动作都是非延续性的 2、He was writing as I was reading. 我看书时，他在写字。（线线重合）两个动作都是延续性的 3、The students were talking as the teacher came in. 老师进来时，学生们正在讲话。（点线重合）前一个动作是延续性的，而后一个动作时非延续性的 二、while的意思是“在……同时（at the same time that )”“在……期间(for as long as, during the time that）”。从while的本身词义来看，它只能表示一段时间，不能表示具体的时间点。在时间上可以是“线线重合”或“点线重合”，但不能表示“点点重合”。例如： 1、He was watching TV while she was cooking. 她做饭时，他在看电视。（线线重合） 2、He was waiting for me while I was working. 我工作的时候，他正等着我。（线线重合） 3、He asked me a question while I was speaking. 我在讲话时，他问了我一个问题。（点线重合）
过去进行时 过去进行时表示过去某一时刻或者某段时间正在进行或发生的动作，常和表过去的时间状语连用，如： 1. I was doing my homework at this time yesterday. 昨天的这个时候我正在做作业。 2. They were waiting for you yesterday. 他们昨天一直在等你。 3. He was cooking in the kitchen at 12 o'clock yesterday. 昨天12点，他正在厨房烧饭。 过去进行时的构成： 肯定形式：主语+was/were+V-ing 否定形式：主语+was not (wasn't)/were not (weren't)+V-ing 疑问形式：Was/Were+主语+V-ing。 基本用法： 1. 过去进行时表示过去某一段时间或某一时刻正在进行的动作。常与之连用的时间状语有，at that time/moment, (at) this time yesterday (last night/Sunday/week…), at+点钟+yesterday (last night / Sunday…)，when sb. did sth.等时间状语从句，如： 1）What were you doing at 7p.m. yesterday? 昨天晚上七点你在干什么？ 2）I first met Mary three years ago. She was working at a radio shop at the time. 我第一次遇到玛丽是在三年前，当时她在一家无线电商店工作。 3）I was cooking when she knocked at the door. 她敲门时我正在做饭。 2. when后通常用表示暂短性动词，while后通常用表示持续性动词，而while所引导的状语从句中，谓语动词常用进行时态，如： When the car exploded I was walking past it. = While I was walking past the car it exploded. 3. when用作并列连词时，主句常用进行时态，从句则用一般过去时，表示主句动作发生的过程中，另一个意想不到的动作发生了。如： I was walking in the street when someone called me. 我正在街上走时突然有人喊我。 4. when作并列连词，表示“（这时）突然”之意时，第一个并列分句用过去进行时，when引导的并列分句用一般过去时。如： 1）I was taking a walk when I met him. 我正在散步，突然遇见了他。 2）We were playing outside when it began to rain. 我们正在外边玩，这时下起雨来了。 过去进行时和一般过去时的用法比较： 1）过去进行时表示过去正在进行的动作，而一般过去时则表示一个完整的动作。 例如：They were writing letters to their friends last night. 昨晚他们在写信给他们的朋友。（没有说明信是否写完） They wrote letters to their friends last night.
when，while，as引导时间状语从句的区别 when，while，as显然都可以引导时间状语从句，但用法区别非常大。 一、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。 ①Why do you want a new job when youve got such a good one already？（get 为短暂性动词）你已经找到如此好的工作，为何还想再找新的？ ②Sorry，I was out when you called me．（call为短暂性动词）对不起，你打电话时我刚好外出了。 ③Strike while the iron is hot．（is为延续性动词，表示一种持续的状态）趁热打铁。 ④The students took notes as they listened．（listen为延续性动词）学生们边听课边做笔记。 二、when从句的谓语动词可以在主句谓语动作之前、之后或同时发生；while 和as从句的谓语动作必须是和主句谓语动作同时发生。 1．从句动作在主句动作前发生，只用when。 ①When he had finished his homework，he took a short rest．（finished先发生）当他完成作业后，他休息了一会儿。 ②When I got to the airport，the guests had left．（got to后发生）当我赶到飞机场时，客人们已经离开了。 2．从句动作和主句动作同时发生，且从句动作为延续性动词时，when，while，as都可使用。 ①When ／While ／As we were dancing，a stranger came in．（dance为延续性动词）当我们跳舞时，一位陌生人走了进来。 ②When ／While ／As she was making a phonecall，I was writing a letter．（make为延续性动词）当她在打电话时，我正在写信。 3．当主句、从句动作同时进行，从句动作的时间概念淡化，而主要表示主句动作发生的背景或条件时，只能用as。这时，as常表示“随着……”；“一边……，一边……”之意。 ①As the time went on，the weather got worse．（as表示“随着……”之意） ②The atmosphere gets thinner and thinner as the height increases．随着高度的增加，大气越来越稀薄。 ③As years go by，China is getting stronger and richer．随着时间一年一年过去，中国变得越来越富强了。 ④The little girls sang as they went．小姑娘们一边走，一边唱。 ⑤The sad mother sat on the roadside，shouting as she was crying．伤心的妈妈坐在路边，边哭边叫。 4．在将来时从句中，常用when，且从句须用一般时代替将来时。 ①You shall borrow the book when I have finished reading it．在我读完这本书后，你可以借阅。 ②When the manager comes here for a visit next week，Ill talk with him about this．下周，经理来这参观时，我会和他谈谈此事。 三、when用于表示“一……就……”的句型中（指过去的事情）。 sb．had hardly（＝scarcely）done sth．when．．．＝Hardly ／Scarcely had sb．done sth．when．．．
一、从句是如何出题的 1. 时态 2. 考连接词 3. 考语言顺序 二、学好从句的两个基本条件 1. 时态 2. 从句的三个必须:①必须是句子；②必须有连接词；③必须是陈述句 三、状语从句、宾语从句、定语从句重点 1.如何判断何种从句 2. 从句的时态 3. 从句的连接词与扩展 4. 经典单选、从句与选词、长句子分析 四、如何判断三种从句 1. 状语从句无先行词 2. 宾语(表语)从句无先行词有动词或词组 3. 定语从句先行词多为名词或代词 一、When引导的定语从句与时间状语从句的区分 1. when的译法不同。在时间状语中，when 翻译成“当……的时候”I want to be a teacher when I grow up. 当我长大的时候，我要做一名老师。在定语从句中，when不翻译。I won't forget the day when he says he loves me. 我不会忘记他说爱我的那一天。 2. 在时间状语中，when从句前面或后面是句子；定语从句中，when从句不能位于句首，且通常when前为表示时间的名词day、year等。 3. when在从句的作用不同。在时间状语从句中，when是连词，只起连接主句和从句的作用，不做从句的任何成分。不过when引导的时间状语从句修饰主句的谓语，做主句的时间状语。 在定语从句中，when是关系副词，在从句中代替先行词做从句的时间状语，修饰从句的谓语。 例1 I will always remember the days when I lived with my grandparents in the country. 例2 I always remember the days in the country when I see the photo of my grandparents. 点评：例1意为“我会永远记得跟我祖父母一起住在乡下的那些日子”，其中when 引导的是一个定语从句, 修饰the days, when在从句中作时间状语。例2意为“当我看到祖父母的照片时，总是会想起在
When while as的区别和用法 when的用法 当主句使用持续性动词时. Dave was eating,when the doorbell rang.门铃响时,大卫在吃饭. 2.一个动作紧接着另一个动作发生. When the lights went out, I lit some candles.灯灭了,我赶紧点上一些蜡烛. 3.谈论生命中的某一阶段,或过去的某段时间. His mother called him Robbie when he was a baby. 在他很小时,他妈妈叫他Robbin. 4.指"每一次" When I turn on the TV, smoke comes out the back. 每当我打开电视,就有烟从后面冒出. while/as 的用法 从句多为进行时,而且为持续性动词. I'll look after the children while you are making dinner. 你做饭,我来照顾孩子. 注意事项: (1) “主短从长”型：主句表示的是一个短暂性动作，从句表示的是一个持续性动作，三者都可用： He fell asleep when [while, as] he was reading. 他看书时睡着了。 Jim hurt his arm while［when，as］he was playing tennis. 吉姆打网球时把手臂扭伤了。 As［When，While］she was waiting for the train，she became very impatient. 她在等火车时，变得很不耐烦。 (2) “主长从长”型：若主、从句表示两个同时进行的持续性动作，且强调主句表示的动作延续到从句所指的整个时间，通常要用while： Don’t talk while you’re eating. 吃饭时不要说话。 I kept silent while he was writing. 在他写的时候，我默不做声。 但是，若主从句表示的两个同时进行的动作含有“一边…一边”之意思，通常用as：
when 和while的用法区别 ①when是at or during the time that, 既指时间点，也可指一段时间； while是during the time that，只指一段时间，因此when引导的时间状语从句中的动词可以是终止性动词，也可以是延续性动词，而while从句中的动词必须是延续性动词。 ②when 说明从句的动作和主句的动作可以是同时，也可以是先后发生；while 则强调主句的动作在从句动作的发生的过程中或主从句两个动作同时发生。 ③由when引导的时间状语从句，主句用过去进行时，从句应用一般过去时；如果从句和主句的动作同时发生，两句都用过去进行时的时候，多用while引导，如： a. When the teacher came in, we were talking. 当此句改变主从句的位置时，则为： While we were talking, the teacher came in. b. They were singing while we were dancing. ④when和while 还可作并列连词。when表示“在那时”；while表示“而，却”，表对照关系。如： a. The children were running to move the bag of rice when they heard the sound of a motor bike. 孩子们正要跑过去搬开那袋米，这时他们听到了摩托车的声音。 b. He is strong while his brother is weak. 他长得很结实，而他弟弟却很瘦弱。 when，while，as引导时间状语从句的区别 when，while，as显然都可以引导时间状语从句，但用法区别非常大。 一、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。 ①Why do you want a new job when youve got such a good one already？（get 为短暂性动词）你已经找到如此好的工作，为何还想再找新的？ ②Sorry，I was out when you called me．（call为短暂性动词）对不起，你打电话时我刚好外出了。 ③Strike while the iron is hot．（is为延续性动词，表示一种持续的状态）趁热打铁。 ④The students took notes as they listened．（listen为延续性动词）学生们边听课边做笔记。 二、when从句的谓语动词可以在主句谓语动作之前、之后或同时发生；while和as从句的谓语动作必须是和主句谓语动作同时发生。 1．从句动作在主句动作前发生，只用when。 ①When he had finished his homework，he took a short rest．（finished先发生）当他完成作业后，他休息了一会儿。 ②When I got to the airport，the guests had left．（got to后发生）当我赶到飞机场时，客人们已经离开了。 2．从句动作和主句动作同时发生，且从句动作为延续性动词时，when，while，as都可使用。
when和while的用法和区别 while和when都是表示同时，到底句子中是用when还是while主要看从句和主句中所使用的动词是短暂性动作（瞬时动词）还是持续性动作。 1、若主句表示的是一个短暂性的动作，而从句表示的是一个持续性动作时，两者都可用。如：He fell asleep when [while] he was reading. 他看书时睡着了。 I met him when [while] I was taking a walk in the park. 我在公园散步时遇到了他。 2、若主、从句表示两个同时进行的持续性动作，且强调主句表示的动作延续到从句所指的整个时间，通常要用while。如： Don’t talk while you’re eating. 吃饭时不要说话。 I kept silent while he was writing. 在他写的时候，我默不作声。 3、若从句是一个短暂性动作，而主句是一个持续性动作，可以when 但不用while。如：When he came in, I was listening to the radio. 他进来时，我在听收音机。 It was raining hard when we arrived. 我们到达时正下着大雨。 4、若主、从句表示的是两个同时(或几乎同时)发生的短暂性动作，一般要用when。如： I thought of it just when you opened your mouth. 就在你要说的时候，我也想到了。 至于什么是短暂性动作，什么是持续性动作，其实有个很简单的规律。就是如果是进行时态，一般是持续性的。如果是过去式，一般是短暂性动作。 对于，填写when还是while的问题，通常首先看主句和从句中的时态，再根据以上4个规律来判断填写那个单词。 When和While的区别 通常when 后面接一般过去时while 后面接过去进行时 ①when是at or during the time that, 既指时间点，也可指一段时间，while是during the time that，只指一段时间，因此when引导的时间状语从句中的动词可以是终止性动词，也可以是延续性动词，而while从句中的动词必须是延续性动词。 ②when 说明从句的动作和主句的动作可以是同时，也可以是先后发生；while 则强调主句的动作在从句动作的发生的过程中或主从句两个动作同时发生。 ③由when引导的时间状语从句，主句用过去进行时，从句应用一般过去时；如果从句和主句的动作同时发生，两句都用过去进行时的时候，多用while引导，如： a. When the teacher came in, we were talking. 当此句改变主从句的位置时，则为： While we were talking, the teacher came in. b. They were singing while we were dancing. ④when和while 还可作并列连词。when表示“在那时”；while表示“而，却”，表对照关系。如： a. The children were running to move the bag of rice when they heard the sound of a motor bike.
While和When在过去进行时中两者的区别如下： ①when是at or during the time that, 既指时间点，也可指一段时间；while是during the time that，只指一段时间，因此when引导的时间状语从句中的动词可以是终止性动词，也可以是延续性动词，而while 从句中的动词必须是延续性动词。 ②when 说明从句的动作和主句的动作可以是同时，也可以是先后发生；while 则强调主句的动作在从句动作的发生的过程中或主从句两个动作同时发生。 ③由when引导的时间状语从句，主句用过去进行时，从句应用一般过去时；如果从句和主句的动作同时发生，两句都用过去进行时的时候，多用while引导，如： a. When the teacher came in, we were talking. 当此句改变主从句的位置时，则为： While we were talking, the teacher came in. b. They were singing while we were dancing. ④when和while 还可作并列连词。when表示“在那时”；while表示“而，却”，表对照关系。如： a. The children were running to move the bag of rice when they heard the sound of a motor bike. 孩子们正要跑过去搬开那袋米，这时他们听到了摩托车的声音。 b. He is strong while his brother is weak. 他长得很结实，而他弟弟却很瘦弱。 when; while 当……时候 while能用when代替; 但是when却不一定能用while代替. while+从句, 动作一定会延续 when+延续性动词/瞬间动词; when he arrived
when和while when和while都可表示“当……的时候”，引导时间状语从句。你知道两者在过去进行时中的用法有什么不同吗？ 请仔细观察下面的例句，然后补全空格中的内容。 ①I was walking to school when I saw a cat in a tree. ②When Sally arrived home, her mother was cleaning the house. 主句的动作是持续性的，而从句动作是短暂性的，此时用_______引导时间状语从句，主句用_____________时态，从句用一般过去时态。 ③While I was sleeping in the bedroom, someone knocked at the door. ④David fell while he was riding his bike. 主句的动作是短暂性的，从句的动作是持续性的，此时用_________引导从句，主句用____________时态，从句用过去进行时态。 ⑤While Andy was waiting for the bus, he was reading a newspaper. ⑥He was cleaning his car while I was cooking. 主句和从句的动作在过去的某时刻或某段时间同时发生，而且动作都是持续性的，此时用_________引导从句，而且主句和从句都用_____________ 时态。 练习：用when 和while 填空 1. We were singing __________ the teacher came in. 2. _________ I was doing my homework , my mother was cooking. 3. What were you doing _________ the rainstorm came ? 4. ________ I was waiting for the bus at the bus station, it began to rain. 5. ________ he woke up, the smoke was rising.