If引导条件状语从句的详细用法解答

If引导条件状语从句的详细用法解答

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。

4．if从句用一般现在时，主句用一般现在时

If you heat ice it turns to water. (也可用will turn)如果把冰加热，它就会化成水。

5．if从句用现在进行时，主句用一般将来时

If you are looking for Peter you’ll find him upstairs. 如果你是在找彼得，上楼就会找到他。

6．if从句用现在完成时，主句用一般将来时

If you have finished dinner I’ll ask the waiter for the bill. 如果你吃完了，我就叫服务生来算账

注意 ：

学习\" if \" 引导的条件状语从句的用法,现在总结一下:

if 条件句不一般,几个要点记心间;

条件句,放在前,逗号要放句中间。

条件句表可能，主句多用将来时；

条件句表事实，主句常用现在时。

在 if 引导的条件状语从句中，如果从句谈论的是一个有可能发生的事实及其产生的相关的结果，主句用一般将来时态，从句用一般现在时态。如：

We can walk there if we can't find a bus .

If it rains tomorrow ,we will not go to the zoo.

What will you do if you find a panda in danger.

如果 if 条件句谈论的是重复发生和预示要发生的情景和事件，则主从句大多用一般现在时态。如：

If bears are in danger ,they attack people.

在 if 引导的条件状语从句中，if 和条件句位置灵活，可直接放在主句后面，若 if 条件句放句首， 从句后面要加逗号，和主句隔开。还要注意前后时态一致原则

【边学边做】用括号内所给词的正确形式填空。

1. What will you buy if you ________（have）a lot of money?

2. If it ________（not snow）tomorrow, we will feel unhappy.

3. You mustn’t go to school if you ________（be）still in bed.

4. If he _______（be）at home at that time, he would know it.

5. Please show me the way if you ________（know）it.

6. You will hurt your teeth if you ________（eat）too much candy.

7. If you gave me a toy car, I _________（be）very happy.

8. I would get the prize if I _________（work）hard.

9．If she ______ (finish ) work early ,she ______(go) home.

10．If the weather______（be）fine，we_______(go)for a walk .

11. If I_____(have) time tonight ,I _______(finish) the book I’m reading.

12. If it ______(rain) next weekend , we_______(not be able to ) plant the vegetable .

13. If it_______(rain),we______(stay) at home .

14.If she______(arrive) ,she _____(phone) me .

15. If he_____(call),tell him I’ll ring back .

二、用所给词的适当形式填空

1. If you ________(feel) tired, you _________ (have) to have a rest.

2. Where _____ he ____(see) the film if he _________(have) time?

3. If there ____ (be) fewer trees, there _______ (be) more pollution.

4. He ___ (dress) more casually if he ___ (not work) on weekends.

5. If Marcia _______ (live) alone, she _______ (keep) a pet parrot.

6. Lana _____ (buy) a new dress if the old one ____ (be) out of style.

7. The twins _______ (fight) if they__________ (argue).

8. I ______ (have) a bake sale if I ____ (need) money for education.

9. Peter ____ (send) me a beautiful souvenir if he ____(tour) Spain.

10. If Mr. Green _______ (say) I am hard- working, my parents ___ (feel) glad.

11. I ______ (go) to the beach if it________ (not rain) this week.

12. _____they ___ (have) a match if the P.E. teacher __ (be) busy?

13. He ____ (write) a letter to his grandparents if he ____ (get) his report card this week.

14. If she ______ (get) up late, she _____ (not catch) the early bus.

15. Peter ____ (major) in English if he ____(pass) the exams in Peking University.