if条件状语从句ppt课件

1、Adverbial Clause of Conditionif 引导的条件状语从句引导的条件状语从句-复习课复习课1If you are happy, what will you do? If I am happy, I will smile.2If you become sad, what will you do?If I become sad, I will cry.3She is doing her homework.If you are hard-working, you will get good grades.She gets good grades.4If you play co

2、mputer games on weekdays ,youll be very tired in classyour parents will be sad.you wont get good grades.your eyes will be poor5She will be late.If she _ to school, she _ _late. She is going to walk to school.walkswillbe61) 条件状语从句通常由if或或unless(=if not)引导，从句中常用一般时代替将来时一般时代替将来时，即if或unless后的句子谓语用一般现在时。但

3、是，主句则通常用将来时，情态动词或祈使句。 时态主将从现时态主将从现主句一般将来时，主句一般将来时，从句一般现在时从句一般现在时71. 如果主句是一般将来时，从句则用一般现在时。如果主句是一般将来时，从句则用一般现在时。 If it rains（从句），（从句）， I will stay at home. Ill go with you if you dont want to go alone（从句）（从句）. 2.如果主句含有如果主句含有must, may, can 等情态动词，从句也要用等情态动词，从句也要用一般现在时。一般现在时。 If you drive too fast, you m

4、ay have an accident. You must stop if the traffic is red.3. 如果主句是祈使句，从句同样要用一般现在时。如果主句是祈使句，从句同样要用一般现在时。 Dont go and play football if you dont finish your homework. Please call me if he comes next Sunday. if条件状语从句结构及时态条件状语从句结构及时态Revision8 If 引导条状语从句时，从句中用一般现在时代替一般将来时。1. If he _(go) to the movies,he wo

5、nt finish his work.goes 2. If I _(become) a doctor,I can help others. become3. If we _(have )time, we will go to the park tomorrow.have4.如果你去，如果你去， 我也去。我也去。If you go,I will go.5.如果明天下雨，请带雨衣如果明天下雨，请带雨衣。 raincoatPlease take a raincoat if it rains.9If you are free this weekend,what will you do ?If I am

6、 free ,sleepwatch TVplay computer gamespractice10If you want to get good marks,do what? Dont do what? If you want to get good marks, _. If you want to get good marks, dont _. study hard listen to teachers carefully. do homework by yourself. copy your homework. talk in the class cheat in the exams11I

7、f you have enough pocket money, what will you buy? If I have enough pocket money, I _.12If you invite foreigners to China, where will you go? I will go to _, if I invite foreigners to China.Mount TaiWest lake Hainan 13 If 条件句的替代形式：条件句的替代形式： （1）祈使句祈使句 + and/or + 陈述句陈述句（谓语动词通常用将来时态）。其（谓语动词通常用将来时态）。其中，

8、中，and表示句意顺承；表示句意顺承；or表示转表示转折，意为折，意为“否则否则”。 e.g. If you work hard, youll pass the exam easily. = Work hard, and youll pass the exam easily. If you dont work hard, youll fall behind others. = Work hard, or youll fall behind others.14（2）用介词用介词with, without的替代形的替代形式：式： e.g. If there is no water, the fis

9、h may die. = Fish may die without water. If you help me, Ill finish my task on time. =With your help, Ill finish my task on time.15 Activity 1 Rewrite the sentences with if:Listen in class, or you wont understand what to do.If you dont listen in class, you wont understand what to do.1) Eat breakfast

10、, or youll get hungry at school.2) Hurry up! Well be late!If you dont eat breakfast, youll get hungry at school.If you dont hurry up, well be late.16Activity2.Complete the sentences I want to get high scores. If _(work hard/ do well)you work hard, you will do well.1.-how can I remember my friends bi

11、rthdays? -If_ (keep a note in your diary / not forget).2.-Its late, but I dont want to go to sleep. -If _ (not get enough sleep/ feel tired at school).you keep a note in your diary, you wont forget.you dont get enough sleep, youll feel tired at school.17If 在宾语从句中翻译为在宾语从句中翻译为“是否是否”If 在条件状语从句中翻译为在条件状语

12、从句中翻译为“如果如果”Ill go to see you if I am free next week. I want to know if he is a teacher.whether1. if 在句中的含义不同在句中的含义不同182. if 在从句中的位置不同在从句中的位置不同If 引导的宾语从句放在主句之后；而引导的宾语从句放在主句之后；而if引引导的状语从句可放在主句之前也可放在主导的状语从句可放在主句之前也可放在主句之后句之后= If it doesnt rain, I will go out tomorrow.I will go out tomorrow if it doesn

13、t rain.I dont know if the train has arrived. If 引导的条件状语从句放于句首时多用逗号隔开；引导的条件状语从句放于句首时多用逗号隔开；而而if引导的宾语从句则不能。引导的宾语从句则不能。193. 时态要求上有区别时态要求上有区别If 引导条件状语从句的时态为一般现在时引导条件状语从句的时态为一般现在时 记住记住“主将从现主将从现” 1.I want to know if there a sports meeting next month.doesnt rainwill be2.If it doesnt rain ,well go outIf 引导的

14、宾语从句的时态由主句及本身时引导的宾语从句的时态由主句及本身时态决定；态决定；201. Can you tell me if she can come to the meeting ?2. She will not go there if it is rainy tomorrow.3. I cant guess if she will be angry .4. If we help each other , we will get good results .211 If I _(not understand）, I will ask my teacher for help .2 If I _

15、(copy ) your homework , I will cheat myself .3 If she _(not get ) up early , shell miss the early bus .4 If your mother_ (buy) the book for you , it will be good for your study. dont understand copy doesnt get buys225. If you _(not work ) hard , you _(not pass) the exam.6. If your brother _(break) t

16、he window , he will feel very sorry for that .7. If the computer (not work), mend it please .dont workwont passbreaksdoesnt work238. If she _(not be) interested in math, she will find it very boring .9. If you _(get ) high scores, your parents will be proud of you .10. If you _(be) happy , we will b

17、e happy .isnt getare 24. I want to know if he _(come)tomorrow, if he _(come), I _(give) the message to him. comes will come will give25if的用法的用法2.引导条件状语从句：引导条件状语从句：译为译为“如果，假如如果，假如”(1) if从句从句+祈使句祈使句(2) if从句从句+主句（一般将来时）主句（一般将来时）(3) if从句从句+主句（含有情态动词）主句（含有情态动词） 1.引导宾语从句引导宾语从句：译为：译为“是否是否”，表示不确定的概，表示不确定的概念

18、。念。I dont know if your father can come together . Can you tell me if miss your parents ?261.If you _ to the party, youll have a great time. A. will go B. went C. go D. going2 I _ her the answer if she _me. A.can tell, will ask B. will tell, will ask C. would tell, ask D. will tell, asksCD3. What are

19、 you going to do tomorrow? -Well go to the library tomorrow if it _. A. isnt rain B. rain C. wont rain D. doesnt rain4. What will you do if you _ to the old folks home visit? A. go B. went C.going D. will goAD275. If I eat _ food, Ill be very fat. A. too many B. many too C. too much D. much too6. Il

20、l give the book to him if he _ here next Sunday. A. will come B. comes C. is coming D. came 7. There _an English film in our school tomorrow. A. is going to have B. will have C. is going to be D. has8. Could you tell us where _？ A. will the next Olympic Games held B. the next Olympic Games will be held C. would the next Olympic Games be held D. the next Olympic Games would be heldCCBB28If引导的非真实性条件状语从句（虚拟语气）引导的非真实性条件状语从句（虚拟语气） (A)与现实事实相反与现实事实相反 主：过去将来时主：过去将来时 从：过去时从：过去时 If they were here ,they would help you. (B)与过去事实相反与过去事实相反 主：主：s