if引导的条件状语从句讲与练
引导条件状语从句最常用的连词是if，常见的if条件状语从句表示在某条件下，某事很可能发生，条件是可能存在的，主句中某种情况发生的概率也是很高的
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。
If you have finished the homework， you can go home．如果你作业做完了就可以回家了。另外，if从句还表示不可实现的条件或根本不可能存在的条件，也就是一种虚拟的条件或假设。从句多用一般过去时或过去完成时，表示对现在或过去的一种假设。如：
If I were you，I would invite him to the party．如果我是你，我会邀请他参加聚会。
I would have arrived much earlier if I had not been caught in the traffic．要不是交通堵塞，我本会来得早一些。另外你还要注意if 条件句的时态搭配
1．if从句用一般现在时，主句用一般将来时
If he runs he’ll get there in time. 如果他用跑的，他就会及时赶到那儿。
The cat will scratch you if you pull her tail. 如果你拉猫的尾巴，它就会抓你。
2．if从句用一般现在时，主句用may/might/can
If the fog gets thicker the plane may/might be diverted.
如果雾在大一些，飞机可能就会改在别的机场降落。
If it stops snowing we can go out. 如果雪停了，我们就可以出去。
3．if从句用一般现在时，主句用must/should
If you want to lose weight you must/should eat less bread. 如果你想减肥，你必须少吃面包。一．单项选择
)1. I don’t know if it ______tomorrow. If it ______,we won’t go on a picnic.
A. rains;rains
B. will rain;rains
C. will rain;will rain
( )2. In summer , food goes bad easily ________ it is put in the refrigerator.
A. until
B. if
C. Unless
( )3. --I hear Jack Chan will come to Laiwu next week.
--Really? _______ he comes, my younger sister will be very happy,
A．If B．Until C．Unless D．Before
( )4. Could we play football in your playground, Sir ?
--No,_______ you have the principal’s note.
A.if
B.unless
C.because
D.since
( )5. Many children like fried chicken _______it is unhealthy food.
A.if
B.because
C.although
( )6. All the students in Class 5 will climb the mountain if it _______ rain tomorrow.
A. won’t
B. don’t
C. didn’t
D. doesn’t
( )7 ---Would you like to go bike riding with us tomorrow?
---Sure, ________ I am busy.
A. since
B. unless
C. when
D. until
( )8. I don’t like bread. I won’t eat it ________ I am very hungry.
A. when
B. unless
C. if
( )9. You’d better look up the new word in a dictionary _____ you don’t know i
A if B. that C. though D. Whether
( )10. After the meeting, we will have a party. If you _______ free, come and join us.
A. are
B. will be
C. Were
）11.If you _____ to the party, you’ll have a great time
A. will go
B. went
C. go
D. going
12What are you going to do tomorrow? --We’ll go to the library tomorrow if it ___.
A. isn’t rain
B. rain
C. won’t rain
D. doesn’t rain
13. What will you do if you __ to the old folk’
s home visit? A. go B. went C. going D. will go
14. If I eat ____ food, I’ll be very fat. A. too many B. many too C. too much D. much too
15. Ill give the book to him if he ___ here next Sunday.
A. will come
B. comes
C. is coming
D. came
16. I ____ her the answer if she ____me.
A. can tell, will ask
B. will tell, will ask
C. would tell, ask
D. will tell, asks
17. Well go to the farm and help the farmers with the apple-picking if it ____ tomorrow.
A. won’t rain
B. will be rainy
C. doesn’t rain
D. isn’t raining
18There is going to _______ a sports meeting next week. If it ________,
we’ll have to cancel it. A. be, will rain B. have, will rain C. be, rains
19 Your teacher will be unhappy if you _______ to school late.
A. come
B. will come
C. are coming
D. came
20．I don’t know if he __. If he __ , please let me know.
A. comes, comes
B. will come, will come
C. will come, comes
D. comes, will come
二、用所给词的适当形式填空。
1.If she ______________(not get) home on time, her mom will be worried.
2.If Tom works hard, he_____________(make) a lot of money.
3.If I study hard, my dream ___________(实现).
4. If he ____________(争论)his friend, he will be very sad.
5.If you fight with your brother, what _____________(发生)?
6. Call me if he ________________(回来).
7. He can make great progress if he ____(追随，听从) my advice.
( )8. If I find his phone number, I ______ you. A. tell B. told C. will tell D. have told
)9. I __ the CDs to you if I have time tomorrow.
A. will return
B. returned
C. have returned
D. return
( )10. The students will go to the Summer Palace if it ________tomorrow.
A. won' t rain
B. isn' t raining
C. doesn' t rain
D. isn' t rain
( )11. I wont watch the TV play if my father ___ me do my homework.
A. let
B. will let
C. won’t let
D. lets
( )12. If you ___quiet, Ill tell you what happened. A. will B. are C are to be D be
( )13. If you go to the party, you ___ a good time. A. would have B. have C. will have D. had ( )14. Dont worry. Peter will call you as soon as he _____ London.
A. will get to
B. gets to
C. get to
D. got to
( ) 15.He doesnt tell me when he ____. Ill telephone you as soon as he _____.
A. will come, comes
B. will come, will come
C. comes, will come
D. comes, comes
( )16.-- I dont know if Dr. White ______ to the party next week.
– I think he will come if he ______ free.
A. comes; will come
B. will come; will be
C. comes; is
D. will come; is
