条件状语从句PPT课件PPT课件

1、引导条件状语从句的连接词主要有：if(如果)、unless(除非)或 as long as(只要)等。条件状语从句第1页/共19页引导条件状语从句最常用的连词是if 。如果你请他帮忙,他会帮你的。If you ask him, he will help you.如果你考试不及格,你会让他失望的。If you fail in the exam, you will let him down. 如果你作业做完了就可以回家了。 If you have finished the homework，you can go home.条件状语从句第2页/共19页unless = if.not. 除非,若不,除

2、非下雨,比赛将照常进行。Unless it rains, the game will be played.If it doesnt rain, the game will be played.让我们出去散步吧，除非你太累了。Lets go out for a walk unless you are too tired.If you are not too tired, lets go out for a walk.条件状语从句第3页/共19页 1. 除非你早点动身，你就不能及时赶到那儿。 You will fail to arrive there in time unless you star

3、t earlier You will fail to arrive there in time if you dont start earlier2.除非天气不好，我每天早晨都要去慢跑。 Unless bad weather stops me，I go jogging every morning If bad weather doesnt stop me，I go jogging every morning 3. 除非你需要，我不会借钱给你的。 I wont lend you money unless you are in need I wont lend you money if you a

4、re not in need 第4页/共19页3、so/as long as只要只要你保持书的清 洁，你就可以把我的书借去。You may borrow my book as/so long as you keep it clean. 只要你高兴，你做什么都没有关系。 So/As long as youre happy, it doesnt matter what you do.只要你努力，你就会成功。Youll succeed as (so ) long as you try hard.条件状语从句第5页/共19页时态问题在条件状语从句中，要注意主将从现的规定，即主句用一般将来时，从句用一般

5、现在时表示将来时。我有时间，我就来看你。I will come to see you if I have time. 条件状语从句第6页/共19页If 从句 （一般现在时），主句 （ 一般现在时 ） 表示科学常识，经常性的动作 1.如果水被加热，它会变成蒸汽。 If water is heated, it turns to steam. 2. 如果我需要理发，我通常去我家附近的理发店。 If I need a haircut, I usually go to the barbers near where I live. 3.如果天下雨，人们通常星期天不出门。 People often dont

6、 go out on Sundays if it rains.第7页/共19页表示将来的可能性时，运用“主将从现”的原则。 1. 如果我得到这项工作，我将会买个手机。 If I get the job, Ill buy a mobile phone. 如果我的家庭作业很难，我会叫Helen帮助我。 2. If my homework is difficult, Ill ask Helen to help me. 如果我今天下午有时间，我将去和同学踢足球。 3. If I have time this afternoon, Ill go to play soccer with my classm

7、ates.第8页/共19页典型例题： If he _in half an hour, we _wait for him.A. wont come ,wont B. wont come ,dontC. doesnt come ,wont D. will come ,dont条件状语从句第9页/共19页误区提醒if 既可以引导条件状语从 句，表示如果，也可以引导宾语从句，表达是否。辨别它在这两种从句中的时态是我们经常容易出错的地方。另外，if 和unless的用法也需注意条件状语从句第10页/共19页1. If it _tomorrow, we _ to climb mountains. A. d

8、oesnt rain; go B. wont rain; will go C. wont rain; go D. doesnt rain; will go 2Do you know if _ tomorrow morning? No. I will call you if she _ back. A. she will come; comes B. she comes; will come C. will she come; comes D. will she come; will come条件状语从句第11页/共19页3Well go to the park if it_ rain tomo

9、rrow. A. dont B. doesnt C. wont 4We are not sure if it _ tomorrow. If it _ , our sports meeting will be put off. A. rains; rains B. rains; will rain C. will rain; will rain D. will rain; rains条件状语从句第12页/共19页5. Ill give the book to him as long as he _ here next Sunday. A. will come B. comes C. is com

10、ing D. came 6.You will not get good grades _ you work hard. A. and B. unless C. if D.as long as 条件状语从句第13页/共19页 40. Will you please give the dictionary to Jane? Sure, Ill give it to her _ she arrives here.A. before B. until C. because D. as soon as第14页/共19页37. A snake bit him _ he went to see a doctor at once. A. if B. where C. because D. so第15页/共19页 28. You will be late for school_ you dont get up early. A. but B. if C. and D. or第16页/共19页34. It was raining heavily, _ we decided to stay at home and watch T