时间、原因、条件状语从句(知识梳理)

时间、原因、条件状语从句

真题再现

1. I believe you will have a wonderful time here you get to know everyone else.

A. thought

B. as if

C. once

D. so that

2. If you miss this chance, it may be years ____ you get another one.

A. As

B. before

C. since

D. after

3. We need to get to the root of the problem______ we can solve it.

A. while

B. after

C. before

D. as

4. There is only one more day to go your favorite music group play live.

A. since

B. until

C. when

D. before

5. It is so cold that you can’t go outside ________ fully covered in thick clothes. A. if B. unless C. once D. when

6. You won’t find paper cutting diff icult _____you keep practicing it.

A. even though

B. as long as C .as if D. ever since

7. _____the damage is done, it will take many years for the farmland to recover.

A. Until

B. Unless

C. Once

D. Although

1. C。句意：我相信一旦你了解这里的每个人，你将玩得很愉快。though虽然；as if好像；once一旦；so that为了。所以选C。

2. B。此题考查的知识点是状语从句。句意：如果你错过了这次机会，也许要等若干年后你才能得到另一个机会。before引导的时间状语从句，在……之前还需要多长时间。故B正确。

3. C。本句考查的是时间状语从句的用法。句意：在我们解决问题之前，我们需要找到问题的根源。A. while当……时候；B. after在……之后；C. before 在……之前；D. as一边一边，强调动作同时进行。故选C。

4. D。句意：在你最喜欢的乐队现场表演前，就剩一天时间了。since表示“自从……以来”。until表示“直到……”。when表示“当……的时候”，before意为“在……前”，符合题意。

5. B。本题考查状语从句连词的用法，句意为：外面很冷你不要出去，除非身上盖个厚厚的毯子。

6. B。句意：只要你不断练习，你不会觉得剪纸很难。本题考查状语从句。even though即使；虽然；as long as只要；as if犹如；好像；ever since 自从。

7. C。句意：一旦农田被毁坏，将需要许多年的时间才能得以恢复。本题考查状语从句。until“到……为止；直到……才；”unless“如果不；除非”；once“一旦，一经……便”；although“虽然；然而；尽管”。

知识讲解

时间状语从句

一、普通从属连词

引导时间状语从句的普通类从属连词有when（当……时），while（在……期间），as（当……，一边……一边……），before（在……之前），after（在……之后），since（从……以来），till/until （直到），whenever（无论何时），as soon as（一……就）等。

When I went into the classroom, he was reading.

He read a newspaper as he went along.

We must strike while the iron is hot.

I will tell you after they leave.

I told him to come back whenever he wants to.

I waited till/until she was back.

Once time is gone, you will never get it back.

注意：在时间状语从句中，不能用一般将来时、过去将来时态或将来完成时，而要用相应的一般现在时态、一般过去时或现在完成时来代替。

I’ll telephone you as soon as I get there.

Don’t get off the bus until it has stopped.

二、含time的短语

可引导时间状语从句的time 短语有every time, each time, (the) next time, (the) last time, by the time, the first time, any time 等。

Every time I listen to music, I’ll think of it. 每当我听音乐，我就想起这事。

He didn’t tell me anything the last time I saw him. 上次我见到他时他什么也没告诉我。

Each time she moved her head she let out a moan. 她每转动一下头，就发出一声呻吟。

三、表示“一……就……”

除as soon as外，还有三类：

名词型——the moment, the minute, the second, the instant；

副词型——immediately, directly, instantly；

句式型——no sooner…than…, hardly/scarcely…when…。

The moment I saw him I knew that there was no hope.

I came immediately you called.

I had no sooner got home than it began to rain.

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.

四、对before从句的理解

before的本意为“在……之前”，根据具体语境还可理解为“还没来得及/还没有……就……，趁着还没……就……，不知不觉就……，……才……”等。

I had not sat long before he came back. 我没坐多久他就回来了。

He almost knocked me down before he saw me. 他几乎把我撞倒才看到我。

Before I could get in a word, he measured me. 我还来得及插话，他就给我量好了尺寸。

I’ll water the flowers before it gets dark. 我要趁着天还没黑把花浇好水。

Be a pupil before you become a teacher. 先做学生，后做先生。

Time passed quickly and three months went by before she knew it. 时间过得飞快，她不知不觉就在那里度过了三个月。

I will die before I will betray my country. 我宁可死也不会背叛我的国家。

五、对since从句的理解

1. since从句的谓语动词是终止性动词照字面意思理解。

I’ve been feeling down since I lost my job. 自从失去工作后,我的情绪一直处于低潮。

2. since从句谓语动词延续性动词，且为现在完成时时，仍然按字面意思理解。

She has never come to see me since I have lived in the city. 自从我住到城里，她就一直不来看我。

3. since从句谓语动词延续性动词，且为一般过去时时，按与字面意思相反的意思理解。

I have made great progress since I was ill. 我自病愈以来取得了很大的进步。

4. since前有ever，或从句谓语动词是be且后接表示人成长过程中的某个阶段或年龄的名词、形容词时，仍然按字面意思理解。

I have lived here ever since I was a child. 我从还是个孩子时就一直住在这儿。

六、对till/until从句的理解

1. 主句为肯定式，主句谓语动词必须为持续性动词，且该动词所表示的动作或状态一直延续到until / till 从句所表示的时间为止，可译作“（直）到……”。

He waited until/till I returned. 他一直等到我回来。

2. 主句为否定式（包括含no, nobody, nothing, never, hardly, little 等否定词的肯定句），若主句谓语动词是非持续性动词，则该动词所表示的动作在until / till 从句表示的时间开始发生。一般先译从句“直到……”，后译主句，not 译成“才”，即“直到……才……”。

His mother didn’t leave until/till he wa s asleep. 直到他睡着了，他母亲才离开。

Nobody can leave until/till the meeting is over. 直到散会才能离开。

3. 主句为否定式，若主句谓语动词是持续性动词，则须根据上下文去理解until/till从句的含义，一般译为“直到……才……”或“没有到……”。

He didn’t wait until/till I returned. 他没有等到我回来。

She didn’t sleep until/till I returned. 她直到我回来才睡着。

原因状语从句

引导词：because, as, since, for

—Why did you do it?

—I did it because I was angry.

It was because I was angry that I did it.

I didn’t help him, not because I was unwilling but because I was unable to.

only, just, simply, partly + because

You shouldn’t look down upon a man just because he is poorly dressed.

as（由于，因为）引导的从句一般放在主句之前，说明原因，后边的主句说明结果。主从句的内容同等重要。在主句之后时，语气更弱；类似一种附带的说明，在口语中使用较多。As there was no answer, I wrote again.

I got home late as I had to walk all the way home.

for是表示因果关系的并列连词，表示对主句内容的补充说明（可和because替换）或表示一种推测判断（不可用because）。它引导的从句不能放在句首；需有逗号与主句隔开。

He seldom goes out, for he is too old.

He must be asleep now, for there is no light on.

We listened attentively, for he was going to tell us who won it.

注意：以上连词不能与so同时使用。

条件状语从句

条件状语从句主要由if, unless, as/so long as, on condition that, suppose/supposing that, provided that, in case 等引导。

I’ll fire if you come any nearer.

You could get a better job if you spoke a foreign language.

Unless you wear boots you may be bitted by snakes.