if条件状语从句

Adverbial Clause of Conditionif 引 导 的 条 件 状 语 从 句-复习课 If you are happy, what will you do? If I am happy, I will smile. If you become sad, what will you do?If I become sad, I will cry. She is doing her homework.If you are hard-working, you will get good grades.She gets good grades. If you play computer games on weekdays ,youll be very tired in classyour parents will be sad.you wont get good grades.your eyes will be poor She will be late.If she _ to school, she _ _late. She is going to walk to school.walks will be 1) 条件状语从句通常由if或unless(=if not)引导，从句中常用一般时代替将来时，即if或unless后的句子谓语用一般现在时。

但是，主句则通常用将来时，情态动词或祈使句 时态主将从现主句一般将来时，从句一般现在时 1. 如果主句是一般将来时，从句则用一般现在时 If it rains（从句）， I will stay at home. Ill go with you if you dont want to go alone（从句）. 2.如果主句含有must, may, can 等情态动词，从句也要用一般现在时 If you drive too fast, you may 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 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Revision 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 wont 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， 我也去。

If you go,I will go.5.如果明天下雨，请带雨衣 raincoatPlease take a raincoat if it rains. If you are free this weekend,what will you do ?If I am free , sleepwatch TVplay computer gamespractice If 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 exams If you have enough pocket money, what will you buy? If I have enough pocket money, I _. If you invite foreigners to China, where will you go? I will go to _, if I invite foreigners to China.Mount Tai West lake Hainan If 条件句的替代形式： （1）祈使句 + and/or + 陈述句（谓语动词通常用将来时态）。

其中，and表示句意顺承；or表示转折，意为“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. （2）用介词with, without的替代形式： e.g. If there is no water, the fish 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. 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, 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. Activity2.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 birthdays? -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. If 在宾语从句中翻译为“是否”If 在条件状语从句中翻译为“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 2. if 在从句中的位置不同If 引导的宾语从句放在主句之后；而if引导的状语从句可放在主句之前也可放在主句之后= If it doesnt rain, I will go out tomorrow.I will go out tomorrow if it doesnt 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；而if引导的宾语从句则不能。

3. 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 记住“主将从现” 1.I want to know if there a sports meeting next month.doesnt rain will be2.If it doesnt rain ,well go outIf 引导的宾语从句的时态由主句及本身时态决定； 1. 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 . 1 If I _(not understand）, I will ask my teacher for help .2 If I _(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 buys 5. If you _(not work ) hard , you _(not pass) the exam.6. If your brother _(break) the window , he will feel very sorry for that .7. If the computer (not work), mend it please .dont workwont pass breaksdoesnt work 8. 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 be happy .isnt getare . I want to know if he _(come)tomorrow, if he _(come), I _(give) the message to him. comes will come will give if的用法2.引导条件状语从句：译为“如果，假如”(1) if从句+祈使句(2) if从句+主句（一般将来时）(3) if从句+主句（含有情态动词） 1.引导宾语从句：译为“是否”，表示不确定的概念。

I dont know if your father can come together . Can you tell me if miss your parents ? 1.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 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 goA D 5. If I eat _ food, Ill be very fat. A. too many B. many too C. too much D. much too6. Ill 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 heldCC BB If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 主：过去将来时 从：过去时 If they were here ,they would help you. (B)与过去事实相反 主：should/would +have +v.(p.p.) 从：had+v.(p.p.) E. If he had worked harder ,he would have succeeded. BY THE TIME by the time +一般过去时，从句过去完成时 by the time +一般现在时，从句现在完成时 nerdn.令人厌烦的人；愚蠢的人；落伍的人；电脑迷shrug v.耸肩（表示不知道或不在乎） shrug sth off/aside不把当回事；对满不在乎；对不予理睬 dirt n.泥土;污垢，污泥;下流想法;恶意中伤的话 His clothes were covered in dirt.他的衣服沾满了污垢。

hand n.手;协助，帮助;（工具等的）把，柄;掌管 vt.传递，交给;搀扶;支持 Several of his colleagues had a hand in his downfall.他的几位同事对他的下台起了作用 gratituden.谢意;感激，感谢;感激的样子;恩义He smiled at them with gratitude .他向他们笑了笑表示谢意 underestimate vt.低估;看轻;对估计不足;把的价值估计过低 Never underestimate your opponent.决不可低估你的对手 impactn.影响;碰撞，冲击，撞击;冲击力 vt.撞击;挤入，压紧;对产生影响the environmental impact of tourism旅游事业对环境的巨大影响 。