if引导的条件状语从句

语法10单元语法再现梁老师组稿2017-12-31

一、观察下面的句子

If you go to the party, you will have a great time.

If you do , you will be late.

If you do,you will be sorry.

If they have it today, half the class won’t come.

If we ask people to bring food, they will just bring potato chips and chocolate.

以上几个句子中“if”有相同的含义“如果”，引导条件状语从句逗号后面的句子是主句。整个连起来的大句子叫主从复合句。

注意主句和从句的时态有什么特点。

总结：If引导的条件状语从句用一般现在时，主句用一般将来时。

简称“主将从现”

练习：（1）If you ______(come)here, you ___________(be) happy.

(2) If it _________(rain) tomorrow, we__________(not, go) to the park.

(3) If he _________(come) here, I ___________(call) you.

(4) If it ___________(not rain), we _________(have) a picnic(野餐).

(5) If we do that, more people _________(want) to play the games.

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(6) If they _______ that , the games _______(be) more exciting, too.

(7)What ______ happen if they_______ (have) the party today?

(8) What ______ happen if they _______ a video at the party?

(9) If he ______(take) a taxi, it _______(be) too expensive.

(10) If I _______(go) to the movies, I ____________(finish) my homework.条件状语从句的引导词还有“unless 除非（否则），如果不”

You won’t pass the exam unless you study hard.

Unless you deal with(处理）your problems, you will be unhappy.

二、同样when可以引导状语从句“主将从现”也适合

也就是说：when引导的时间状语从句也是一般现在时，

主句也是一般将来时。

What are you going to be when you grow up?

What is he going to be when he grows up?

三、“主将从现”的含义扩充

主：表示主句

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将：（1）主句是一般将来时

（2）主句是祈使句

（3）主句含有情态动词can、may、must/have to

从：表示状语从句

现：表示状语从句是一般现在时

例句：

(1)Don't go and play football if your homework ______________(not finish) .

(2)If it ____________(not rain) tomorrow, we ______________(go)to climb the hill.

(3)He wo n't leave until you _______________(agree)with him.

(4) You can cross the road when the lights _________(turn) green.

(5)I _____________(call)you as soon as he ____________(tell) me about the good news.

(6)The students will go to Summer Palace if it __________ tomorrow.

A. don't rain

B.won't rain

C. doesn't rain

D. isn't rain

四、if 翻译成“是否”，引导宾语从句，时态是：一般将来时。

例如：I don’t know if he will come tomorrow.

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V.

He asks me if I will be free .

V.

They want to know if they will have a party next week.

V.

注意把if的两个意思放在一道题中考试。（主将从现宾将）Mary wants to know if Tom will come. If he comes, I will call Mary.

练习：

1.I don't know if it _____ tomorrow. If it ____ , we'll go out for a picnic.

A. will rain; doesn't rain

B. will rain; rains

C. rains ; will rain

2.---Does Ted tell you if he ___next Sunday?

---No, he doesn't. But if he ___. I'll give you a ring.

A. will come; will come

B. comes; will come

C. comes ; comes

D. will come; comes

3. ---I wonder if it ____tomorrow.

---Don't worry. If it ____, we'll stay at home.

A.rains; rains

B. will rain; rains

C. rains; will rain

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