if 引导的条件状语从句（讲义）
状语
用来表示行为发生的时间、地点、目的、方式、程度等，通常由 副词或介词短语充当，也可由一个句子充当。
I slept at home yesterday because I had a bad cold.
状语从句
状语从句指句子作状语。
根据其作用可分为时间、地点、原因、条件、目的、结果、让步、 方式等从句。
状语从句一般由连词（从属连词）引导。
I will go to school by bike tomorrow if it is sunny. Grammar focus
—I think I ' ll take the bus to the party.
—If you do, you ' ll be late.
If you take the bus to the party, you
—I think I ' ll stay at home.
—If you do, you ' ll be sorry. If you stay at home, you ' ll be sorry.
—What will happe n if they have the party today?
——If they have it today, half the class won
—Should we ask people to bring food?
—If we ask people to bring food, they and chocolate.
1 if 在本单元句中意为“ _______________ ； _______ ”，用于引导
即if 引导的是一个完整的句子，所以一定要有主谓，成为从
句，另一个句子则成为主句。
If you go there, I ' ll go, too.
We will go hiking if it doesn ' t rain tomorrow.
If Bob leaves tomorrow, I will hold a party for him toni ght.
2 if 引导的条件状语从句既可以放在主句前，也可放在主句后。
但是如果放在主句前，即句首时，从句后面要用
与主句
隔开。
You will keep healthy if you do more exercise. If you do more
ll be late.
t come. ll just bring potato chips
exercise, you will keep healthy.
3时态：if引导的条件状语从句用____________________ 表示将来，主句可以使用一般将来时，含有情态动词的句子或者祈使句。
主将从现If you practice speaking English more, you will like it better. If she
goes to New York tomorrow, I will go there, too.
My sister will be very happy if our uncle comes n ext week. 练习：
If Nancy ______ the exam, she will go to Australia for En glish
study.
A. pass
B. passed
C. passes
D. will pass
If the weather ______ fine, we ______ have a sports meeti ng n ext weeke nd.
A. will be; will
B. is; will
C. was; would
D. was; will
主情从现
If you get up at six tomorrow morning, you can catch the first bus.
If you go to study in America n ext year, you must lear n En glish hard.
主祈从现
Let ' s go out for a walk if it doesn ' t rain tomorrow. If you see a snake in the forest, don ' t move!
unless
也可引导条件状语从句，表示“如果不，除非” Unless
he comes here in an hour, I will go there alone. If he doesn' t come here in aour, I will go there alone.
You will feel worse unl ess you go to see the doctor right now.
You will feel worse if you don ' t go to see the docto练ight now.
习：
______ y ou read it, you can ' t imagine how interesting tise story A. U nless _ B. Because C. Although D. If
—Please give Alice the story book _______ y ou see her.
—All right.
A. unless
B. or
C. but
D. if
Exercises
、单项选择
)1. Study ing in groups is n ecessary in
school.
exam.
11. 如果你不告诉我原因，我会告诉妈妈这件事
12. 我不会去医院的，除非你和我一起去那儿。
【参考答案】
you want to do well A. if B. un til C. uni ess )2. — Will you help me with the trouble?
—I won't _you tell me the truth.
B. but
C. after
D. though A. if D. uni ess )3. If Bob
health.
_away from the junk food, he will be in good A. stay
B. will stay )4. If Tom _____ the game, we A. win
B. wi ns )5. we llgo to the park if it ____ A. won' rain
)6. If you
A. do
)7. If there _
C. stays
D. stayed 'll give himuaprise. C. won D. wi nning tomorrow. B. don' rain C. doesn ' rain D. rain recaorful, you B. will do ____ much better. C. are doing D. did and selli ng of ani mals, there no buying ____ no killi ng in n ature. A. is; will be
C. is; is )8. I ' m waiting myr friend. swimmi ng alone. A. does nt c ome; go C. won ' t comwjll go
二、翻译
9. 如果明天不下雨，我会去看你的。
If it ______________ tomorrow, I
10. 如果Mary 不为考试做准备，她会不及格。
If Mary _____________________ the exam, she B. will be; will be D. will be; is
If he ________ , I
B. won ' t comgo D.
doesn ' t come; wgo you. fail the
Grammar focus
1. 如果；假如；条件状语从句
2. 逗号
3. 一般现在时主将从现
练习：
unless
练习：
A D
Exercises
一、单项选择
1-5 ADCBC
6-8 BAD
二、翻译
9. doesn' t rain; wiVisit
10. doesn' t prepare fcwjll
11. If you don ' t tell me the reason, I will tell mom thi sg.
12. I won ' t go to the hospital uni ess you go there witle.
4。