考点三十八 时间状语从句
1. 引导时间状语从句的连词
从属连词 | 用法 | 例句 |
While | ＂与……同时，在……期间＂，从句常用延续性动词或表示状态的词 | Don’t talk loud while（as豆腐的作用）others are working. 别人工作时，请勿大声说话。 |
When | ＂当……时＂，表示主句的动作和从句的动作同时或先后发生，从句的动词可用延续性动词，也可用非延续性动词 | It was raining when we arrived. 我们到达时，天正下着雨。 when you read the poem a cond time, the meaning will become clearer to you. 当你再读一遍这首诗，你就会更清楚它的含义。 |
As | ＂正当，一边……一边，随着＂，表示两个动作同时发生或某事发生时，另一个动作发生了 | 大榕树作文As time went on, his theory proved to be correct. 随着时间的推移，他的理论被证明是正确的。 |
Till/Until | 用于肯定句时，表示＂直到……为止＂，主句必须为延续性动词；until/till表示＂直到……才＂，主句常用短暂性动词 | 马蒂斯的画We shall wait until/till he comes back. 我们将一直等到他回来。 I didn’t leave until/till she finished her homework. 直到她完成作业我才离开。 |
Since | ＂自……以来＂，主句用一般现在时或现在完成时，从句用一般过去时 | I have heard lot of good things about you since I come back from abroad. 自从我从国外回来，我已经听许多好的事情。 |
Before | 在……以前 | He must finish all the work before he goes home. 回家之前他必须完成所有的工作。 |
After | 在……之后 | Let’s play football after school. 放学后我们打篮球吧。 |
【知识拓展】 时间状语从句的时态问题：在时间状语从句和条件状语从句中，主句如果使用一般将来时态，从句使用一般现在时表示将来，即所谓的＂主将从现＂。 As soon as I arrive in Beijing, I will ring you up. 我一到北京就给你打电话。 You’ll fall behind the others unless you study hard. 如果你不努力学习，你将会落后于其他人。 |
人民大学研究生 | | |
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? 二手烟对孩子的危害
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 wor. 随着时间的过去，天气变得更糟糕了。
The atmosphere gets thinner and thinner as the height increas.
《童年》读书笔记
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.
I had hardly / scarcely clod my eyes when someone knocked at the door.
＝Hardly / Scarcely had I clod 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 ts.）
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积重难返’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.
关于体育的论文
注意：否定句可用另外两种句式表示。
（3）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
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
when/before, 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.
