英语时间状语从句讲解与练习
（一）when, while 和 as 引导时间状语从句的用法
一、when 的用法
如果只从现象来看，when 从句用的最多的是一般过去时，而主句的时态没有限制, 根据具体情况而定。
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。
根据以上的例句，我们可以总结出一点：when 从句的A 事件，相当于另一个事件B 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 多数情况下用的是一般过去时，则不用正在进行时。因为如果用正在进行时，它表示的就是一段时间而不是一个时间点了。根据这一点，有的文章补充说：when 从句的动词大多是瞬时动词。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：
1. When I got to the airport, the guests had left. 当我赶到飞机场时，客人们已经离开了。
2. When he had finished his homework, he took a short rest.
当他完成作业后，他休息了一会儿。
3. Why do you want a new job when you have got such a good one already?
你已经找到如此好的工作，为何还想再找新的？
二、while 的用法
相比于when 来说，while 从句的侧重点就不一样了。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 they were talking, the bell rang. 正在他们谈话的时候，上课铃响了。
2. You can’t do your homework while you’re watching TV. 你不能一边看电视一边做家庭作业。
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 。
三、as 的用法
as 从句表示的也是一件事情正在发生，另一件事也正在进行当中。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。as 从句一般可以翻译成“边……边……”。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. 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。
as 表达的事件，往往只是主句动作发生的背景或条件时，as 只是一个次要的时间说明，不像while 从句有强调 while 动作本身的意思。因此，as 常常翻译成“随着……”之意。
1. As the time went on，the weather got worse. 随着时间的推移，气候更加糟糕。
2. As 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。 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. 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。
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。
五、比较while, when, as
1）as, when 引导短暂性动作的动词。
2）当从句的动作发生于主句动作之前，只能用when 引导这个从句，不可用as 或 while 。
3）从句表示“随时间推移”连词能用as ，不用when 或while 。
例如： As the day went on, the weather got worse. 日子一天天过去，天气越变越坏。
（二）before 和after 引导的时间状语从句
1． Before 是主句动作发生在从句的前面。注意before 引导的从句不再用否定式的谓语，并且当before 引导的从句
位于主句之后，有时译成“就，才”。还要注意主句和从句之间的时间关系。当主句用将来时，从句总是用现在时；如果before 引导的从句谓语用的是过去时，则主句动词多用过去完成时，这样以便体现动作发生的先后。
2． After 表示主句动作发生在从句动作之后。主句和从句的动作的时间关系正好与before 引导的从句相反。例如： It will be four days before they come back. 他们要过四天才能回来。
Einstein almost knocked me down before he saw me.爱因斯坦几乎把我撞倒才看到我。
（三）比较until 和till 的用法
此两个连词意义相同。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。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. 我一直睡到半夜时醒了。 Wait till I call you. 等着我叫你。 （在肯定句中可用before 代替。例如：Let's get in the wheat before the sun sets.）
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。
区别：1）until 可用于句首，而till 通常不用于句首。
例如：Until you told me, I had heard nothing of what happened.
直到你告诉我以前，出了什么事我一点也不知道。
3）N ot until…在句首，主句用倒装。
例如：Not until the early years of the 19th century did man know what heat is.
直到19 世纪初，人类才知道热为何物。
5）It is not until… that….
例如：It was not until I began to work that I realized how much time I had wasted.
（四）巧辨before 和until
一、在下列情况下，两者可互换用，但含义略有不同。before 表示“在……之前”的意思，强 调时间先后关系；而until 表示“直到……才”的意思，主句是肯定句则表示主句动作的终 止时间；主句是否定句则强调主句动作的起始时间。
1. 主句为否定式终止性谓语动词。常见的动词是open,start,leave,arrive,finish,
stop 等。例如：
(1)The noise of the street didn't stop until/before it was midnight.
(2)The children won't come back until/before it is dark.
2. 主句为肯定式、延续性谓语词，这类动词用stand,stay,talk,be,wait 等。例如：
(1)He lived with his parents until/before he graduated from school.
(2)I will wait until/before he comes to my help.
二、在下列情况下，用before 不用until 。
1. 主句这肯定式、终止性谓语动词，只用before 。例：
(1)He fell asleep before I could take off his clothes.
(2)We arrived there before it atarted to rain.
2. 主句谓语动词强调动词的迟缓性，只用before ，常伴有时间段状语或时间段暗示。例：
(1)It was quite some time before he found the elephant at all.
(2)We had walked a long way before we found some water.
3. 如果强调从句谓语动作未发生，就发生主句谓语动作，只用before 。常译为“未及”，“不”或“不等……就”。
(1)We can leave early in the morning before it gets too hot. (2)I must write it down before I forget it.
4. 表“与其说……倒不如”，“与其……毋宁……”只用before 。例：
(1)I would give up my job before I'd agree to be dismissed. (2)He will die of hunger before he will steal.
5. 在某些特定句型中用before 。例如：
(1)It was not long before the whole country rose up.
(2)It will probably not be long before they understand each other.
三、下列情况一般区别用until 。
1. 主句是持续性谓语动词时，肯定、否定都可以，但意义完全不同。肯定表动作终止，而否定表动作开始。
(1)We discussed the problem until/before he came back.我们一直讨论到他回 来。
(2)We didn't discuss the problem until he came back.我们一直等到他回来后才讨论问题。
2.not…until句型尽管在某些情况下可与before 互换用，但在强调句中一般仍用until 。
(1)It was not until he told me that I knew it.
(2)It was not until he finished his homework that he went home.
（五）其他时间状语从句的用法
1. 由since 引导的时间状语从句。
since 引导的从句的谓语动词可以是延续性的动词，又可以是瞬时动词。一般情况下，从句谓语动词用一般过去时，而主句的谓语动词用现在完成时。但在It is ＋时间＋since 从句的句型中，主句多用一般现在时。例如： I have been in Beijing since you left. 自从你离开以来，我一直在北京了。
Where have you been since I last saw you? 自上次我和你见面以后，你到哪里去了？
知识扩展
1. It is since从。。。以来多长时间了(因为since +从句或名词，表示一段时间)
It is five years since we met last time.从我们上次见面已经五年了。
2. It is +before„(。。。才)
It was a long time before I went to sleep again.过了很长时间我才睡着。
It was an hour before(＝until) the police arrived.过了一个小时，警察才来。
2. 由as soon as, immediately, directly, instantly, the moment, the instant, the minute, 等引导的时间状语从句。
这些连词都表示“一„„就”。例如：
I will go there directly I have finished my breakfast. 吃完早饭，我立即到那里去。
As soon as I reach Canada, I will ring you up. 我一到加拿大，就给你来电话。
3. 由by the time引导的时间状语从句。
注意时态的变化：在一般情况下，如果从句的谓语动词用一般过去时，主句的谓语动词用过去完成时；如果主句的谓语动词用一般现在时，主句的谓语动词用将来完成时。例如：
By the time you came back, I had finished this book.到你回来时，我已经写完这本书了。
By the time you come here tomorrow, I will have finished this work. 你明天来这儿的时候，我将已经完成此工作了。 注意：when while as after before as soon as since till /until by the time 在时间状语从句中，要注意时态一致。一般情况下主句是将来时的时候，从句要用一般现在时。
六、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 where he has been.
2．_________ he was speaking, everybody listened carefully.
3．I saw her just _________ she was getting off the train.
4．Have a good look at that man _________ you pass him.
5．It was already eight o'clock _________ we got there.
6. I was about to go out _________ a visitor came.
7．We'll go to the country at the beginning of June, ______ the summer harvest will start.
8. He learned to speak German _________ he was in Berlin.
9. Henry is in charge of the office ________ Mr. Smith is away.
10. I listen to the recorder _________ I have time.
11. He had learned Chinese _________ he came to China.
12. _________ the work was done, we sat down to sum up experience.
13. I haven't seen him _________ he moved to the other side of the town.
14. I waited ________ he came back.
15. It was not ________ he took off his eyeglasses that I recognized him.
16. She likes everything to be in place ________ she starts to work.
17. The thieves ran away _________ they caught sight of the police.
18. They decided to go back home _________ their money ran out.
19. We played outside till sunset, _________ it began to rain。
20. __________ I get to the airport, I will phone you to pick me up.
21. They were about to leave ______ it began to rain.
22. He always stay in bed ______ lunch time.
23. I like playing tennis _________ my younger sister prefers watching ball games.
24. _________ I understand your viewpoint, I don’t agree with you.
25. _______ she grew older, she became more responsible.
二、从A 、B 、C 、D 中选出可以填入空白处的最佳答案。
1. It was quiet ________ those big trucks started coming through the town.
A. before B. after C. until D. unless
2. It seemed only seconds ________ the boy finished washing his face.
A. when B. before C. after D. even if
3. Hardly had he reached the school gate ________ the bell rang.
A. while B. when C. as D. as soon as
4. ________ you begin, I think you must continue.
A. When B. Whenever C. Once D. Even if
5. I remembered you ________ I saw you at the airport.
A. the moment B. while C. after D. once
6. He was about to go to bed ________ the doorbell rang.
A. while B. as C. before D. when
7.________I listen to your advice, I get into trouble.
A. Every time B. When C. While D. Until
8. _____ John was watching TV, his wife was cooking.
A. As B. As soon as C. While D. Till
9. The children ran away from the orchard(果园) ______ they saw the guard.
A. the moment B. after C. before D. as
Key: 1. When 2. While / When 3. as 4. when/as 5. when when 8. while 9. while 10. whenever 11. before 12. After
15. until 16. before 17. as soon as 18. before 19. when 20. As soon as
23. while 24. While 25. As
二、1. C 2. B 3. B 4. C 5. A 6. D 7.A 8.C 9.A
6. when 7. 14. till/until 21.when 22. until 13. since
英语时间状语从句讲解与练习
（一）when, while 和 as 引导时间状语从句的用法
一、when 的用法
如果只从现象来看，when 从句用的最多的是一般过去时，而主句的时态没有限制, 根据具体情况而定。
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。
根据以上的例句，我们可以总结出一点：when 从句的A 事件，相当于另一个事件B 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 多数情况下用的是一般过去时，则不用正在进行时。因为如果用正在进行时，它表示的就是一段时间而不是一个时间点了。根据这一点，有的文章补充说：when 从句的动词大多是瞬时动词。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：
1. When I got to the airport, the guests had left. 当我赶到飞机场时，客人们已经离开了。
2. When he had finished his homework, he took a short rest.
当他完成作业后，他休息了一会儿。
3. Why do you want a new job when you have got such a good one already?
你已经找到如此好的工作，为何还想再找新的？
二、while 的用法
相比于when 来说，while 从句的侧重点就不一样了。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 they were talking, the bell rang. 正在他们谈话的时候，上课铃响了。
2. You can’t do your homework while you’re watching TV. 你不能一边看电视一边做家庭作业。
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 。
三、as 的用法
as 从句表示的也是一件事情正在发生，另一件事也正在进行当中。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。as 从句一般可以翻译成“边……边……”。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. 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。
as 表达的事件，往往只是主句动作发生的背景或条件时，as 只是一个次要的时间说明，不像while 从句有强调 while 动作本身的意思。因此，as 常常翻译成“随着……”之意。
1. As the time went on，the weather got worse. 随着时间的推移，气候更加糟糕。
2. As 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。 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. 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。
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。
五、比较while, when, as
1）as, when 引导短暂性动作的动词。
2）当从句的动作发生于主句动作之前，只能用when 引导这个从句，不可用as 或 while 。
3）从句表示“随时间推移”连词能用as ，不用when 或while 。
例如： As the day went on, the weather got worse. 日子一天天过去，天气越变越坏。
（二）before 和after 引导的时间状语从句
1． Before 是主句动作发生在从句的前面。注意before 引导的从句不再用否定式的谓语，并且当before 引导的从句
位于主句之后，有时译成“就，才”。还要注意主句和从句之间的时间关系。当主句用将来时，从句总是用现在时；如果before 引导的从句谓语用的是过去时，则主句动词多用过去完成时，这样以便体现动作发生的先后。
2． After 表示主句动作发生在从句动作之后。主句和从句的动作的时间关系正好与before 引导的从句相反。例如： It will be four days before they come back. 他们要过四天才能回来。
Einstein almost knocked me down before he saw me.爱因斯坦几乎把我撞倒才看到我。
（三）比较until 和till 的用法
此两个连词意义相同。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。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. 我一直睡到半夜时醒了。 Wait till I call you. 等着我叫你。 （在肯定句中可用before 代替。例如：Let's get in the wheat before the sun sets.）
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。
区别：1）until 可用于句首，而till 通常不用于句首。
例如：Until you told me, I had heard nothing of what happened.
直到你告诉我以前，出了什么事我一点也不知道。
3）N ot until…在句首，主句用倒装。
例如：Not until the early years of the 19th century did man know what heat is.
直到19 世纪初，人类才知道热为何物。
5）It is not until… that….
例如：It was not until I began to work that I realized how much time I had wasted.
（四）巧辨before 和until
一、在下列情况下，两者可互换用，但含义略有不同。before 表示“在……之前”的意思，强 调时间先后关系；而until 表示“直到……才”的意思，主句是肯定句则表示主句动作的终 止时间；主句是否定句则强调主句动作的起始时间。
1. 主句为否定式终止性谓语动词。常见的动词是open,start,leave,arrive,finish,
stop 等。例如：
(1)The noise of the street didn't stop until/before it was midnight.
(2)The children won't come back until/before it is dark.
2. 主句为肯定式、延续性谓语词，这类动词用stand,stay,talk,be,wait 等。例如：
(1)He lived with his parents until/before he graduated from school.
(2)I will wait until/before he comes to my help.
二、在下列情况下，用before 不用until 。
1. 主句这肯定式、终止性谓语动词，只用before 。例：
(1)He fell asleep before I could take off his clothes.
(2)We arrived there before it atarted to rain.
2. 主句谓语动词强调动词的迟缓性，只用before ，常伴有时间段状语或时间段暗示。例：
(1)It was quite some time before he found the elephant at all.
(2)We had walked a long way before we found some water.
3. 如果强调从句谓语动作未发生，就发生主句谓语动作，只用before 。常译为“未及”，“不”或“不等……就”。
(1)We can leave early in the morning before it gets too hot. (2)I must write it down before I forget it.
4. 表“与其说……倒不如”，“与其……毋宁……”只用before 。例：
(1)I would give up my job before I'd agree to be dismissed. (2)He will die of hunger before he will steal.
5. 在某些特定句型中用before 。例如：
(1)It was not long before the whole country rose up.
(2)It will probably not be long before they understand each other.
三、下列情况一般区别用until 。
1. 主句是持续性谓语动词时，肯定、否定都可以，但意义完全不同。肯定表动作终止，而否定表动作开始。
(1)We discussed the problem until/before he came back.我们一直讨论到他回 来。
(2)We didn't discuss the problem until he came back.我们一直等到他回来后才讨论问题。
2.not…until句型尽管在某些情况下可与before 互换用，但在强调句中一般仍用until 。
(1)It was not until he told me that I knew it.
(2)It was not until he finished his homework that he went home.
（五）其他时间状语从句的用法
1. 由since 引导的时间状语从句。
since 引导的从句的谓语动词可以是延续性的动词，又可以是瞬时动词。一般情况下，从句谓语动词用一般过去时，而主句的谓语动词用现在完成时。但在It is ＋时间＋since 从句的句型中，主句多用一般现在时。例如： I have been in Beijing since you left. 自从你离开以来，我一直在北京了。
Where have you been since I last saw you? 自上次我和你见面以后，你到哪里去了？
知识扩展
1. It is since从。。。以来多长时间了(因为since +从句或名词，表示一段时间)
It is five years since we met last time.从我们上次见面已经五年了。
2. It is +before„(。。。才)
It was a long time before I went to sleep again.过了很长时间我才睡着。
It was an hour before(＝until) the police arrived.过了一个小时，警察才来。
2. 由as soon as, immediately, directly, instantly, the moment, the instant, the minute, 等引导的时间状语从句。
这些连词都表示“一„„就”。例如：
I will go there directly I have finished my breakfast. 吃完早饭，我立即到那里去。
As soon as I reach Canada, I will ring you up. 我一到加拿大，就给你来电话。
3. 由by the time引导的时间状语从句。
注意时态的变化：在一般情况下，如果从句的谓语动词用一般过去时，主句的谓语动词用过去完成时；如果主句的谓语动词用一般现在时，主句的谓语动词用将来完成时。例如：
By the time you came back, I had finished this book.到你回来时，我已经写完这本书了。
By the time you come here tomorrow, I will have finished this work. 你明天来这儿的时候，我将已经完成此工作了。 注意：when while as after before as soon as since till /until by the time 在时间状语从句中，要注意时态一致。一般情况下主句是将来时的时候，从句要用一般现在时。
六、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 where he has been.
2．_________ he was speaking, everybody listened carefully.
3．I saw her just _________ she was getting off the train.
4．Have a good look at that man _________ you pass him.
5．It was already eight o'clock _________ we got there.
6. I was about to go out _________ a visitor came.
7．We'll go to the country at the beginning of June, ______ the summer harvest will start.
8. He learned to speak German _________ he was in Berlin.
9. Henry is in charge of the office ________ Mr. Smith is away.
10. I listen to the recorder _________ I have time.
11. He had learned Chinese _________ he came to China.
12. _________ the work was done, we sat down to sum up experience.
13. I haven't seen him _________ he moved to the other side of the town.
14. I waited ________ he came back.
15. It was not ________ he took off his eyeglasses that I recognized him.
16. She likes everything to be in place ________ she starts to work.
17. The thieves ran away _________ they caught sight of the police.
18. They decided to go back home _________ their money ran out.
19. We played outside till sunset, _________ it began to rain。
20. __________ I get to the airport, I will phone you to pick me up.
21. They were about to leave ______ it began to rain.
22. He always stay in bed ______ lunch time.
23. I like playing tennis _________ my younger sister prefers watching ball games.
24. _________ I understand your viewpoint, I don’t agree with you.
25. _______ she grew older, she became more responsible.
二、从A 、B 、C 、D 中选出可以填入空白处的最佳答案。
1. It was quiet ________ those big trucks started coming through the town.
A. before B. after C. until D. unless
2. It seemed only seconds ________ the boy finished washing his face.
A. when B. before C. after D. even if
3. Hardly had he reached the school gate ________ the bell rang.
A. while B. when C. as D. as soon as
4. ________ you begin, I think you must continue.
A. When B. Whenever C. Once D. Even if
5. I remembered you ________ I saw you at the airport.
A. the moment B. while C. after D. once
6. He was about to go to bed ________ the doorbell rang.
A. while B. as C. before D. when
7.________I listen to your advice, I get into trouble.
A. Every time B. When C. While D. Until
8. _____ John was watching TV, his wife was cooking.
A. As B. As soon as C. While D. Till
9. The children ran away from the orchard(果园) ______ they saw the guard.
A. the moment B. after C. before D. as
Key: 1. When 2. While / When 3. as 4. when/as 5. when when 8. while 9. while 10. whenever 11. before 12. After
15. until 16. before 17. as soon as 18. before 19. when 20. As soon as
23. while 24. While 25. As
二、1. C 2. B 3. B 4. C 5. A 6. D 7.A 8.C 9.A
6. when 7. 14. till/until 21.when 22. until 13. since