(完整版)when,while,as讲解与练习
时间状语从句讲解与练习
when, while 和as 引导时间状语从句的用法
这三个词的意思很简单，都有“当……时候”的意思, 但又有区别。
一、when 的用法
观察下面的句子:
1. When he was a child he was always trying out new ideas. 他小时候就常常试验一些新的设想。
2. When she came into my room, I was just reading a book. 她走进我房间时，我正在看书。
3. Were you writing when the teacher came in? 老师进来的时候，你在写信吗？
4. Sorry, I was out when you called me. 对不起，你打电话来的时候我出去了。
5. He was leaving when someone knocked at the door. 他正要走，这时有人敲门。
6. I thought of it just when you opened your mouth. 就在你要说话的时候，我也想到了。
根据以上的例句，我们可以总结出一点：when 从句中的A事件，相当于主句中B事件发生的时间点。也就是说，when 从句的重点不在动作本身发生的状态，而只是把它作为一个时间点，所以when从句多数情况下用的是一般过去时，而不用进行时, 而且, when 从句的动词大多是短暂性动词。这种说法也可以参照。
实际上，when 从句也可以有其它的时态，但几乎也不用进行时，因为它也只是作为一个时间参照点。例如：
When the manager comes here for a visit next week, I’ll talk with him about this.
下周，经理来这参观时，我会和他谈谈此事。
When的特殊用法：
主句（进行时）when 从句（一般时）
I was walking along the street when a ball hit me on the head.
我正沿着路边着，就在这时一个球打在了头上。
此句中的when=at that time, 表示“突然性”
二、while 的用法
while 从句的侧重点在于描述动作正在发生的状态，它的意思是：当while 事件正在发生的时候，另一件事如何如何。所以，while 从句一般用的是正在进行时。而另一件事的状态没有硬性的要求，根据具体情况而定。例如：
1. While my wife was reading the newspaper, I was watching TV.
当妻子正在看报纸的时候，我正在看电视。
2. While Jim was mending his bike, Lin Tao came to see him. 正当吉姆修自行车时，林涛来看他。
3. While they were talking, the bell rang. 正在他们谈话的时候，上课铃响了。
4. You can’t do your homework while you’re watching TV. 你不能看着电视做着作业。
从时间的角度来看，while 表示的是一段时间，是一个过程。这是while 的侧重点。因此，如果含有“一段时间”的含义的时候，就可以用while。
例如：Strike while the iron is hot. 趁热打铁。
这句话中，是说趁着铁是热的这段时间，赶紧打铁。
再例：
—I'm going to the post office.
—While you're there, can you get me some stamps?
while的特殊用法：表示微弱的对比性转折“而”
I like English while my sister likes math.
我喜欢英语而我姐姐喜欢数学。
三、as 的用法
as从句表达的事件，往往只是主句动作发生的背景或条件时，也就是说，主句的动作是伴随着as从句中的动作发生的。因此，as 从句一般可以翻译成“边……边……”，或者“随着……”之意。但与while 从句不同的是，as 从句用的一般不用正在进行时，而只是一般过去时。例如：
1. As my mother sang those old songs, tears ran down her cheeks.
当我妈妈唱起那些老歌时，眼泪顺着她的脸颊流了下来。
2. The students took notes as they listened. 学生们边听课边做笔记。
3. The little girls sang as they went. 小姑娘们一边走，一边唱。
4. As the time went on，the weather got worse. 随着时间的推移，气候更加糟糕。
少数情况下，如果强调动作正在发生，as 从句也可以用正在进行时。这只能算是特例了。
1. The sad mother sat on the roadside, shouting as she was crying.
伤心的妈妈坐在路边，边哭边叫喊。
2. As we were going out, it began to snow. 正当我们出门时，雪开始下起来。
3. He came in as I was going to bed. 我正要上床睡觉，他进来了。
四、when, while, as 的互换
如果从句动作和主句动作同时发生，并且从句动作为延续性动词时，when，while，as 可以互换使用。这种情况下，它们的细微区别恐怕连英、美人自己也说不清了。
1. When /While /As we were dancing, a stranger came in.
当我们跳舞时，一位陌生人走了进来。[dance 为延续性动词]
2. When /While /As she was making a phone call, I was writing a letter.
当她在打电话时，我正在写信。[make为延续性动词]
3. 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。
Until的用法
Until，直到….如果主句是肯定形式，表示的意思是“做某事直至某时”，动词必须是延续性的。如果主句是否定形式，表达的意思是“直至某时才做某事”。动词为延续性或非延续性都可以。正确使用这两个连词的关键之一就在于判断句中的动词该用肯定式还是否定式。
肯定句：I slept until midnight. 我一直睡到半夜。
Wait until I call you. 等着我叫你。
否定句：She didn't arrive until 6 o'clock. 她直到6点才到。
Don't get off the bus until it has stopped. 公共汽车停稳后再下车。
as soon as的用法
as soon as表示“一……就……”的意思。
例如：As soon as I got home, it began to rain. 我一到家天就开始下雨了。
I’ll tell him as soon as he comes.
练习：在下列各句的空格中填入适当的连词
1．_________ he comes tomorrow, I shall ask when he was born.
2．_________ he was speaking, everybody listened carefully.
3．It was already eight o'clock _________ we got there.
4．Have a good look at that man _________ you pass him.
5．I waited ________ he came back.
6. I was about to go out _________ a visitor came.
7．The thieves ran away _________ they saw the police.
8. He learned to speak German _________ he was in Berlin.
9. She likes everything to be ready ________ she starts to work.
10. We played outside till sunset, _________ it began to rain。
11. _______ she grew older, she became more responsible.
初中英语过去进行时(when-while用法)
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
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.
when和while区别及专项练习---含答案
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)
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。
when, while与as用法辨析
when, while与as用法辨析 1. 根据从句动作的持续性来区分 若是“主短从长”型，即主句是一个短暂性的动作，而从句是一个持续性动作，此时三者都可用。如： As [When, While] she was waiting for the train, she became very im patient. 她在等火车时，变得很不耐烦。 若是“主长从长”型，即主句和从句为两个同时进行的动作或存在的状态，且强调主句动作或状态延续到从句所指的整个时间，此时通常要用while。如： I always li sten to the radio while I’m driving.我总是一边开车一边听收音机。 但是，若主句和从句所表示的两个同时进行的动作含有“一边……一边”之意时，则习惯上要用as。如： He swung his arms as he walked. 他走路时摆动着手臂。 若是“主长从短”型，即主句是一个持续性动作，而从句是一个短暂性动作，此时可以用as或when，但不能用while。如： It was raining hard when [as] we arrived. 我们到达时正下着大雨。 2. 根据主句与从句动作是否同时发生来区分 若主句与从句表示的是两个同时发生的短暂性动作，含有类似汉语“一……就”的意思，英语一般要用as (也可用when)。如： The ice cracked as [when] I stepped onto it. 我一踩冰就裂了。 He jumped to his feet as the boss came in. 老板一进来他立刻站了起来。 若主句与从句表示的是两个几乎同时发生的短暂性动作，含有类似汉语“刚要……就”“正要……却”的意思，英语一般要用as(也可用when)，且此时通常连用副词just。如： Just as [when] the two men were leaving, a message arrived. 就在这两个人要离开的时候，突然有了消息。 3. 根据是否具有伴随变化来区分 若要表示主句动作伴随从句动作同时发展变化，有类似汉语“随着”的意思，英语习惯上要用as，而不用when或while。如：
高考英语 状语从句易混连词辨析
1．时间状语从句常见的从属连词有：(注意其汉语意义) 2．when, while, as, before, after, since, until (till) once as soon as, the moment, the minute, immediately, directly, each/every time, the first time, the last time, next time, by the time, whenever等。例如： 3．Every/Each time I was in trouble, he would come to my help. 4．I thought her nice and honest the first time I met her.注意：（1）when, while, as的区别： 5．1)when引导从句时，主从句的动作有先有后，也可以同时进行,从句的动作可以是持续性的，也可以是短暂的。如： 6．When I got to the airport, the plane had already taken off. （主先从后）（短暂性） 7．When I lived there, I used to go to the seaside on Sundays. (同时) （持续性） 8．When the movie ended, the people went back. （从先主后） 9．2)while侧重主从句动作的对比，且从句的动词必须是持续性的。如：10．While we were chatting she was looking at the time table on the wall．11．3)as引导从句时侧重主从句动作同时或几乎同时进行，从句的动作可以是持续性的，也可以是短暂的。如： 12．Sometimes I watch TV as I am having breakfast． 13．4）when和while还可以是并列连词，意思分别是“就在这时”，“然而”。如： 14．I was having a rest on the sofa when the telephone rang．15．They were surprised that a child should work out the problem while they couldn’t .注：并列连词when常用与以下句型中： ①…was/were doing…when…（正在做…突然）
When while as的区别和用法(综合整理)
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：
while、when和as的用法区别
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）
when 和while的用法区别
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,while,as的区别
一、根据从句动作的持续性来区分 1.“主短从长”型：即主句是一个短暂性的动作，而从句是一个持续性动作，此时三者都可用。如： Jim hurt his arm while [when, as] he was playing tennis. 吉姆打网球时把手臂扭了。 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。 注意：as用于引出一个持续性动词表示“在……期间”时，其谓语通常只能是那些含有动作和发展意味的动词，一般不能是那些不用于进行时态的动词(如be, seem, love, want, agree, see, know, have 等)，所以下面一句中的while不能换为as： A：I’m going to the post office. 我要去邮局。 B：While you are there, can you get me some stamps? 当你在邮局时，能帮我买几张邮票吗? 若主句与从句表示的是两个几乎同时发生的动作，含有类似汉语“刚要……就”“正要……却”的意思，英语一般要用as(也可用when)，且此时通常连用副词just。且此时，从句一般用进行时，主句用短暂性动词的一般时态。【注意与六区别】 I caught him just when [as] he was leaving the building. 他正要离开大楼的时候，我把他截住了。 Just as [when] the two men were leaving, a message arrived. 就在这两个人要离开的时候，突然有了消息。 2.“主长从长”型：即主句和从句为两个同时进行的动作或存在的状态，且强调主句动作或状态延续到从句所指的整个时间，此时通常要用while。如： I always listen to the radio while I’m driving. 我总是一边开车一边听收音机。 He didn’t ask me in; he kept me standing at the door while he read the me ssage. 他没有让我进去，他只顾看那张条子，让我站在门口等着。 但是，若主句和从句所表示的两个同时进行的动作含有“一边……一边”之意时，则习惯上要用as。如： He swung his arms as he walked. 他走路时摆动着手臂。 I couldn’t remember a story to tell the children, so I made one up as I went along. 我想不出有什么故事可给孩子讲了，只好现编现讲。 3.“主长从短”型：即主句是一个持续性动作，而从句是一个短暂性动作，此时可以用a s或when，但不能用while。如：
when while用法区别
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
辨析while, when, as 配套练习
辨析while, when, as 配套练习 1. 用while, as或when填空。 _____spring comes round, warm and cheerful, shall we meet again? 解析： 填When。句意为：句意：当春天再来时，天气温暖令人愉快，我们再见面好吗？若主从句所表示的动作不是同时发生，而是有先后顺序时，一般要用when。所以填When。 2.用while, as或when填空。 _____ the roses are yet in bloom, will you come with me to see them? 解析： 填While。句意为：趁玫瑰花还开着，你和我一起去看看好吗？while可以表示“趁着”，所以填While。 3. 用while, as或when填空。 _____ spring warms the good earth, all flowers begin to bloom. 解析： 填As。句意为：句意：随着春天送暖，大地复苏，各种花儿开始盛开怒放。若要表示两个正在发展变化的情况，相当于汉语的“随着”，一般用as。所以填As。 4. 用while, as或when填空。 If you don’t work hard _____ you are young, you may regret _____ you are old. 解析： 填while; when。句意为：如果你不趁着年轻时努力，当你年老时，你会后悔的。第一个空表示“趁着”，填while；第二个空表示动作不是同时发生，而是有先后顺序时，一般要用when。 5.用while, as或when填空。 He was driving along ____ suddenly a woman appeared. 解析： 填when。句意：他正在开车，突然一个女人出现了。when可用作并列连词，表示“这时(突然)”，所以填when。
when和while的用法和区别
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.
when和while的用法
when和while的用法 when, while这两个词都有"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, Miao Kiukun broke in.在我睡觉时,MIAO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。
常见时态辨析
Grammar ?simple past, past progressive, past perfect ?verbs of perception ?special word order with as and though ?present participle phrases used as adverbials simple past, past progressive, past perfect ?simple past tense: verb + -ed or irregular verbs 1) completed action in the past: –I planted these roses a long, long time ago… (L22) –A year and a half later, my grandfather became gravely ill. (L38) 2) habits or facts in the past: –It was my way of saying thank you to God. (L24) –I used to watch him pick roses for his mother. (L25) 3) duration in the past: –For a moment he just stared off into the apple trees. (L10) 4) past tense of verbs such as want, wonder, hope is used for polite inquiries. –I wondered how you liked the film. ?past progressive tense: was/were + v.-ing (present participle) 1) interruption in the past: Use the Past Progressive to indicate a longer action in the past that was interrupted. –I was standing by his rosebush when an uncle came to tell me… (L49) 2) In 1), described above, the Past Progressive is interrupted by a shorter action in the Simple Past. However, you can also use a specific time as an interruption. –Last night at 6 PM, I was eating dinner. *In the Simple Past, a specific time is used to show when an action began or finished. In the Past Progressive, a specific time only interrupts the action. –Last night at 6 PM, I ate dinner.—I started eating at 6 PM. –Last night at 6 PM, I was eating dinner.—I started earlier; and at 6 PM, I was in the process of eating dinner. 3) parallel actions: two or more actions happening at the same time –I was studying while he was making dinner. –They were eating dinner, discussing their plans, and having a good time. 4) atmosphere: a series of parallel actions to describe the atmosphere at a particular time in the past –When I walked into the office, several people were busily typing, some were talking on the phones, the boss was yelling directions, and customers were waiting to be helped. One customer was yelling at a secretary and waving his hands. Others were complaining to each other about the bad service. 5) repetition and irritation with “always”: expressing the idea that something irritating or shocking often happened in the past –I didn’t like them because they were always complaining. 6) “when” vs. “while”: “when” is most often followed by the Simple Past, whereas “while” is usually followed by the Past Progressive. –I was studying when she called. –While I was studying, she called. ?past perfect tense: had + v.pp. (past participle) 1) completed action before sth. in the past: