考点三十八 时间状语从句
1. 引导时间状语从句的连词
2. 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。
① 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。
Why do you want a new job when you’ve 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？ （get为短暂性动词）
Sorry, I was out when you called me.
对不起，你打电话时我刚好外出了。 （call为短暂性动词）
Strike while the iron is hot.
趁热打铁。 （is为延续性动词，表示一种持续的状态）
The students took notes as they listened.
学生们边听课边做笔记。 （listen为延续性动词）
② 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。
a. 从句动作在主句动作前发生，只用 when。
When 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。
When 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。
b. 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。
c. 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。
As the time went on, the weather got worse. 随着时间的过去，天气变得更糟糕了。The atmosphere gets thinner and thinner as the height increases.
随着高度的增加，大气越来越稀薄。
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。
The little girls sang as they went. 小姑娘们一边走，一边唱。
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。
d. 在将来时的从句中，常用when，且从句要用一般时代替将来时。
You shall borrow the book when I have finished reading it.
在我读完这本书后，你可以借阅。
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。
③ 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...
I 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。
I had hardly / scarcely entered my room when the telephone rang.
＝Hardly / Scarcely had I entered my room when the telephone rang.
我刚一走进房门，电话就响了。
3. 比较until和till
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。
I didn’t manage to do it until you had explained how. 直到你教我后，我才会做。
区别：
（1）until可用于句首，而till通常不用于句首。
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。
（2）until when 疑问句中，until要放在句首。
—Until when are you staying?
—Until next Monday.
注意：否定句可用另外两种句式表示。
（3）Not until...在句首，主句用倒装。
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。
Not until I began to work did I realize how much time I had wasted.
直到工作，才认识到我已蹉跎了许多岁月。
（4）It is not until... that...
It was not until I began to work that I realized how much time I had wasted.
（5）表示＂一……就……＂的结构
hardly/scarcely... when/before, no sooner... than 和as soon as都可以表示＂一……就……＂的意思。
I had hardly / scarcely got home when it began to rain. 刚回家，就下起雨来了。
I had no sooner got home than it began to rain.
As soon as I got home, it began to rain.
注意：如果hardly, scarcely 或no sooner置于句首，句子必须用倒装结构。
Hardly / Scarcely had I got home when it began to rain.
No sooner had I got home than it began to rain.
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.
1. （ 安徽中考）Before the sun ____________, we need to get to the top of the mountain.
A. set B. sets C. is setting D. will set
2. （ 湖北宜昌中考）—It has been much easier for me to go to work ____________ shared bikes appeared.
—But they also caused plenty of problems.
A. since B. before C. unless D. though
3. （ 成都中考）Yesterday, I ____________ the subway home when I suddenly found I was on the wrong line.
A. took B. was taking C. had taken
4. （ 天津中考）Tony was drawing a picture ____________ I was doing my homework.
A. if B. because C. while D. until
5. （ 甘肃兰州中考）I will call you as soon as he ____________ here.
A. arrive B. will arrive C. arrives D. arrived
6. （ 黑龙江龙东地区中考）—Do you know when Mrs. White ____________ for dinner this evening?
—No, but I think shewhen she is free.
A. will come; will come B. will come; comes C. comes; will come
7. （﹒黑龙江齐齐哈尔）—I want to know if he ____________ back tomorrow.
—I’ll call you as soon as ____________.
A. will come; will return B. will come; returnsC. comes; will return
8. （﹒江苏南通）It is known to all that the day becomes shorter and shorter ____________ winter comes.
A. before B. when C. until D. since
9. （﹒吉林）I won’t go home ____________ the rain stops.
A. since B. so C. until
10. （﹒福建）The students were singing happily ____________ I passed the school hall.
A. when B. unless C. though
1. （湖南省澧县届九年级下学期中考最后一次模拟）― Could you tell me when he ____________ back?
— Sure. He will come back as soon as he ____________ the classroom.
A. will come; finishes cleaning
B. comes; will finish cleaning
C. will come; will finish to clean
2. （湖南省澧县届九年级下学期中考最后一次模拟）I’ll go to visit your uncle as soon as I ____________ Beijing.
A. get to B. will get to C. got to
3. Mr. Liu has taught us English ____________ he came to our school.
A. until B. because C. though D. since
4. （山东省龙口市兰高镇兰高学校届九年级上学期期中）My father was reading a newspaper ____________ my mother was cooking dinner.
A. when B. whileC. as soon as D. Until
5. （山东省龙口市兰高镇兰高学校届九年级上学期期中）Many students didn’t realize the importance of study ____________ they left school.
A. when B. untilC. as D. after
6. It’s been five years ____________ we met last time.
A. for B. when C. since D. if
7. A good storyteller must be able to hold his listeners’ curiosity(好奇心) ____________ he reaches the end of the story.
A. if B. unless C. after D. until
8. （江苏省句容市、丹阳市届九年级下学期中考网上阅卷第二次适应性检测）The TV programme The Readers (朗读者) was already over ____________ he got back home yesterday.
A. while B. until C. since D. when
9. —What were you doing ____________ the fire happened?
—I was watching TV at home.
A. if B. while C. when D. since
10. ____________ I saw the delivery man（快递员）cycling towards me, I knew that was my gift.
A. As B. Although C. Before D. While
11. Tom didn’t believe how terrible the earthquake was ____________ he experienced one.
A. if B. because C. until D. since
12. It has been about half a term ____________ Sandy went into junior high school.
A. though B. when C. if D. since
跟踪训练
1. When 2. While / When3. as4. when/as5. when
6. when 7. when 8. while 9. while10. whenever
11. before12. After13. since 14. till/until 15. until
16. before 17. as soon as18. before 19. when 20. As soon as
21. when 22. until 23. while24. While 25. As
真题再现
1. B【解析】句意：太阳落山之前，我们需要到达山顶。Before 引导的时间状语从句不能用将来时态，用一般现在时态来代替，主语the sun单三，谓语动词用单数形式；故选B。学&科网
3. B【解析】句意：昨天，当我突然发现我拨错电话的时候，我正在乘地铁回家。这里是when引导的时间状语从句，当某个动词发生的时候，某个动作正在进行，根据题意，故选B。
4. C【解析】句意：Tony 正在画画，而我在做作业。本题考查连词。由前后两句话的 was doing 能发现是两个过去进行时的动作，因此可以选用 while 链接，属于时间状语从句。与 A. if 引导的条件状语从句和 B. because 引导的原因状语从句无关。而 D. until 表示直到，与原句逻辑关系不符。故正确答案为C。
6. A【解析】句意：——你知道怀特太太今晚是否来吃晚饭吗？——不知道。但我认为她有时间的话她会来。问句为宾语从句，根据this evening今晚，可知句子为一般将来时，构成：will do.回答是when引导的时间状语从句。从句是一般现在时，主句应用将来时。故答案是A。
7. B 【解析】句意：——我想知道他明天是否回来。——他一回来我就打电话给你。分析句子得知，在I want to know if he _____back tomorrow中，if引导的宾语从句，意思是＂是否＂而不是＂如果＂，时态不遵循主将从现，根据后文tomorrow，故用一般将来时态will come；下文中as soon as 表示一……就，它引导的时间状语从句，主句是一般将来时，as soon as 引导的条件状语从句用一般现在时，结合句意和语境可知选B。
8. B 【解析】句意：众所周知，当冬天到来时，白天变得越来越短。A. before＂在……之前＂；B. when＂当……的时候＂；C. until＂直到……为止＂；D. since＂既然；由于＂。故选B。
9. C 【解析】句意：直到雨停了我才回家。A. since自从，引导时间状语从句；B. so所以，引导原因状语从句；C. until直到……才，引导时间状语从句。根据句意，可排除A和B，故选C。
10. A 【解析】句意：当我经过学校大厅的时候学生们正在欢快地唱着歌。根据题干前半句The students were singing happily学生们正在欢快地唱着歌，后半句I passed the school hall. 我经过学校大厅可推知句子是一个时间状语从句，when当……时候；unless除非；though尽管，只有A选项符合题意。故选A。
模拟检测
1. A 【解析】句意：——你能告诉我他将什么时候回来吗？——当然可以。他一打扫完教室就会回来。本题第一句是宾语从句，第二句是时间状语从句。根据回答He will come back...可知，本题第一空用一般将来时；第二空主句是一般将来时，as soon as引导的时间状语从句用一般现在时。故选A。
2. A 【解析】句意：我一到北京就去看望你的叔叔。主句是一般将来时，as soon as引导的时间状语从句用一般现在时。故选A。
4. B 【解析】句意：我的父亲正在读报纸，而我的母亲正在做晚饭。when当……时候；while然而，表示两者进行对比；as soon as一……就……；until直到……。此处是我父亲和母亲所做的事进行对比，故用连词while。故选B。
5. B 【解析】句意：许多学生直到离开学校后才认识到学习的重要性。when当……时候；until直到……；as当……时候；after在……之后。not… until…＂直到……才……＂，故选B。
6. C 【解析】句意：自从我们上次见面已经5年了。for因为，为了；when当……时候；since自从；if如果。主句It’s been是It has been的缩写，是现在完成时态，since是自从的意思，引导时间状语从句，从句中用一般过去时态，主句用现在完成时，故选C。
7. D 【解析】句意：一个好的讲故事的人必须能够保持听者的好奇心，直到他到达故事的结尾。if如果，引导条件状语从句；unless除非，如果不；after在……之后；until 直到……时候。根据句意可知，讲故事的人应该保持听者的好奇心一直到故事讲完，故应选D。
8. D 【解析】句意：当他昨天回到家的时候，电视节目《朗读者》已经结束了。A.当……时候；B.直到……；C.自从；D.当……时候。因为get为瞬间动词，故选D。
9. C 【解析】句意：——火灾发生时你在干什么？——我在家看电视。A. if连词，如果，引导条件状语从句；B. while连词，当……时候，引导时间状语从句，谓语动词为延续性动词；C. when连词，当……时候，引导时间状语从句，谓语动词既是延续性动词也可是短暂性动词；D. since连词，自从，引导时间状语从句。happened暂时性动词，故选C。
10. A 【解析】句意：当我看到送货员骑着自行车向我跑来时，我知道那是我的礼物。A. As同时，当……时；B. Although尽管，表转折；C. Before在……之前，表时间；D. While与……同时，表时间。本句是时间状语从句，根据句意，BC两项与句意不合，可排除。as和while都可接时间状语从句，表示主句和从句的动作同时进行，但用法有别。如果主句和从句表示的是两个同时(或几乎同时)发生的短暂性（非持续性）动作，需用 as / when，而不可用while。结合句意和语境，可知选A。
11. C 【解析】句意：汤姆不相信地震有多么可怕，直到他经历了一次地震。A. if连词，如果，引导条件状语从句；B. because连词，因为，引导原因状语从句；C. until连词，直到……，引导时间状语从句，not...until...直到……才……。D. since连词，自从，引导时间状语从句。故选C。
