中考英语专题复习：条件状语从句Word版

条件状语从句

我们知道,引导条件状语从句最常用的连词是if, 由if引导的条件状语从句表示在某种条件下某事很可能发生。如:

If you ask him, he will help you.如果你请他帮忙,他会帮你的。

If you fail in the exam, you will let him down.如果你考试不及格,你会让他失望的。

unless = if not.

Let's go out for a walk unless you are too tired. 如果你不累的话让我们出去走走。

If you are not too tied, let's go out for a walk. 如果你不太累让我们出去。

学习条件状语从句应注意以下几点：

（1）条件状语从句中一般不使用将来时态，尽管主句使用将

来时态，而主句用一般现在时或现在完成时。

【例】

I will come to see you if I have time.

我有时间，我就来看你。

If the rain stops, I shall go out for a walk.

如果雨停了，我就出去散步。

（2）注意条件状语从句在虚拟语气中的使用。

【例】

If I were to I should first of all get the experts to discuss the plan.

如果我真的想做这事，我首先会找专家们讨论我的计划。

(1)表示与现在的情况相反，或将来实现的可能性很小，if从句用过去式（动词be多用were 这个形式），主句用“would／should／could／might＋动词原形”。例如：

If places_______alike, there would be little need for geographers.

A. being

B. are

C. be

D. were

如果各地方都一样，就不需要地理学家了。（1991.6.-4, 答案是Ｄ）。

在表示将来情况的虚拟条件句中，还可以用“were＋to 不定式”或“should＋动词原形”。Jean doesn't want to work right away because she thinks that if she ____ a job, she probably wouldn't be able to see her friends very often.

A) has to get B) were to get

C) had got D) could have got

吉不想立刻工作，因为她想：如果她得到一份工作，她就不能经常去看她的朋友了。(96.1-44, B对）

( 2) 表示与过去的事实相反，从句用过去完成时，主句用“would／should／could／might ＋have＋过去分词”。如:

If the policeman had arrived earlier, he would have seen the accident.

要是警察更早些到达，他就能见到事故了。

(3) 注意如果以上两类条件句中含有助动词、情态动词，be或have, 则常常不用if，而用倒装结构：

____ before we depart the day after tomorrow, we should have a wonderful dinner party.

A) Had they arrived B) Would they arrive

C) Were they arriving D) Were they to arrive

如果我们后天走之前他们到达的话，我们就举行一次丰盛的宴会。 (97.1-34, D对）（3）条件状语从句中的省略。

【例】

Come tomorrow if possible. 可能的话，明天来。

I will buy a DVD set if necessary.

必要的话，我就买一台DVD。

那么,除了if之外,是否还有其他连词也可以引导条件状语从句呢?回答是肯定的,不仅有,还有很多。这些词由于出现的频率较小,且用法较复杂一些,所以不如if为大家所熟知罢了。下面就这些词的用法以例句的形式进行一下简单总结。

1. unless conj.除非,若不,除非在……的时候

You will fail to arrive there in time unless you start earlier.如果你不早点动身,你就不能及时赶到那儿。

Unless it rains, the game will be played.除非下雨,比赛将照常进行。

2. on condition(that)...在……条件下,如果

on condition (that)...引导的条件从句是主句事件发生的前提条件或唯一条件。

I can tell you the truth on condition that you promise to keep a secret.我可以告诉你真相,条件是你答应保守秘密。

You can go swimming on condition (that) you don't go too far from the river bank.你只有在不远离河岸的条件下才可以下水游泳。

3. supposing conj.如果,假如

supposing引导的条件从句表示一种假设条件。

Supposing it rains, shall we continue the sports meeting? 倘若下雨,我们的运动会还要继续举行吗?

Supposing something should go wrong, what would you do then? 假如出了什么问题,你准备怎么对付?

4. provided conj.假如,除非,以……为条件

provided (that) +从句表示一种假设条件。

He will sign the contract provided we offer more favorable terms.如果我们提出更优惠的条件,他就会在合同上签字。

He won't be against us in the meeting provided that we ask for his advice in advance.如果我们提前征求一下他的意见,他就不会在会上反对我们。

从上述例句可以看出if, unless, on condition (that), supposing, provided等词引导的条件状语从句,主从句条件关系分明,结构清晰。但有些句子,虽没有含条件关系的连词,却也隐含着条件关系,这些句子常用一些词,如but for, without等引出一个介词结构来表示条件,条件常常是虚拟的,或与事实相反的假设。如:

but for 若非,要不是

But for the rain, we should have a pleasant journey.要不是下雨,我们的旅行肯定会很愉快。

But for your help, we should not have finished in time.要不是你帮忙,我们肯定不能及时完成任务。

练习：

单项选择

1. You will be late ____ you don’t leave immediately.

A. unless

B. until

C. if

D. or

2. ____ you keep ice-cream in a fridge, it melts.

A. Unless

B. Until

C. If

D. Or

3. If you ____ a fish out of water, it ____ .

A. will take/will die

B. take/dies

C. will take/dies

D. took/dead

4. If you _____ your timetable every night, you ____ which books to take.

A. will check/will know

B. check/know

C. will check/know

D. check/will know

5. You ____ toothache if you ____ your teeth regularly.

A. will have/clean

B. will have/do not clean

C. have/will clean

D. will have/will not clean

6. I ____ the police and complain about that noise unless it ____ soon.

A. shall telephone/stops

B. shall telephone/does not stop

C. telephone/will stop

D. telephone/will not stop

7. If you ____ the tickets with you, we ____ to enter the cinema.

A. do not take/will not allow

B. take/will not allow

C. do not take/will not be allowed

D. take/will not be allowed

8. If the fish ____ from the bird’s mouth, the bird will swallow it.

A. won’t remove

B. won’t be removed

C. doesn’t remove

D. isn’t removed

9. If the rain doesn’t stop, you can enjoy ____ here for another day.

A. stay

B. to stay

C. staying

D. stayed

10. Don’t put your umbrella over there, or you will forget ____ it home.

A. take

B. to take

C. taking

D. took

11.____ I know the money is safe, I shall not worry about it.

A. Even though

B. Unless

C. As long as

D. While

12. Don't be afraid of asking for help ____ it is needed.

A. unless

B. since

C. although

D. when

13. I would appreciate it ____ you call back this afternoon for the doctor's

appointment.

A. until

B. if

C. when

D. that

14. You will succeed in the end ____ you give up halfway.

A. even if

B. as though

C. as long as

D. unless

15.You will be late ___ you leave immediately.

A. unless

B. until

C. if

D. or

16. You will be late for school _______ you leave now.

A. if

B. when

C. because

D. unless

17. If I get a job, I _________ as a teacher.

A. work

B. will work

C. works

D. worked

18. If it________ tomorrow, we’ll go to the park.

A. will not rain

B. rains

C. doesn’t rain

D. isn’t rain

19.You will do much better ________ you are more careful with oyur spelling.

A. if

B. before

C. although

D. unless

20. All of us will be happy _____ you can come with us.

A. while

B. if

C. but

D. or

答案：

CABDB

BACBA

CDDDA

DBCAB

将由unless与if…not构成的句子进行改写。

1.You won’t pass your exams unless you study hard.

2.We’ll play outside this afternoon unless it rains.

3.If he doesn’t come in the next time minutes, I’m leaving.

4.Leave without me unless I phone.

5.You can’t send a letter unless you know the address.

6.You can’t go in if you’re not a member.

7.Don’t include them if they don’t reply.

答案：

1.You won’t pass your exams if you don’t study hard.

2.We’ll play outside this afternoon if it doesn’t rains.

3.Unless he comes in the next time minutes, I’m leaving.

4.Leave without me if I don’t phone.

5.You can’t send a letter if you don’t know the address.

6.You can’t go in unless you are a member.

7.Don’t include them unless they reply.

有所给词的适当形式填空。

1.If you _________ the key, the door___________.

2.If we _________ too much noise, the neighbours __________.

3.He won’t be able to go to ___________ if the typhoon__________.

4.If you _________ the forests, the environment__________.

5.James _________ himself if he__________ off that ladder.

6.The students ________ their exams if they _______ hard.

7.I ________ a new car if I ___________ a pay rise.

8.She ________ it if you ________ it more clearly.

答案：

1. turn will open

2. make will complain

3. hiking gets

4. burn will suffer

5. will hurt falls

6. will pass study

7. will buy have

8. will understand explain

（注：可编辑下载，若有不当之处，请指正，谢谢!）