1、If引导的条件状语从句引导的条件状语从句潘店镇中学 1PPT课件例句例句：If people obey the traffic rules,there will be fewer accidents.if引导的条件状语从句引导的条件状语从句if:从属连词，意思是：从属连词，意思是：“如果，假如，倘若如果，假如，倘若”从句从句主句主句There There willwill be fewer accidents be fewer accidents if if people obey the traffic rules.people obey the traffic rules.原句可改为：原句
2、可改为：if引导的条件状语从句既可以放在句子前，引导的条件状语从句既可以放在句子前，也可以放在句子后。也可以放在句子后。从句位于主句之前时，常用逗号将其与主句隔开从句位于主句之前时，常用逗号将其与主句隔开。结构结构：2PPT课件主句谓语中也可以含有情态动词，主句谓语中也可以含有情态动词，如：如：must,can,could,should等等时态时态：if引导的条件状语从句，引导的条件状语从句，主句用一般将来时（主句用一般将来时（will）,从句用一般现在时。从句用一般现在时。例句例句：If people obey the traffic rules,there will be fewer ac
3、cidents.主句谓语中也可以用主句谓语中也可以用had better(not)do,提建议提建议例句例句：如果交通指示灯是红的，你必须停下来等一等。如果交通指示灯是红的，你必须停下来等一等。eg:If the traffic lights are red,you must stop and wait.例句：如果你想减肥，你最好锻炼。例句：如果你想减肥，你最好锻炼。eg:If you want to lose weight,you had better take some exercise.3PPT课件if的反义词：的反义词：if.not.=unless,意思是：意思是：“如果不，除非如果不
4、，除非”I wont go there unless I hear from you.(同义同义句句)I wont go there _ I _hear from you.if dont I wont go to the party if I am not invited.(同义同义句句)I wont go to the party_ I am invited.unless4PPT课件变换：变换：1.有有if引导的条件状语从句的复合句中，当主句和从句的引导的条件状语从句的复合句中，当主句和从句的主语均为主语均为you时，可转换为时，可转换为“祈使句，祈使句，and+简单句简单句”或或“祈使句，
5、祈使句，or+简单句简单句”You can pass the exam if you work hard.-，and you will pass the exam.If you dont hurry up,you will be late again.Hurry up,-you will be late again.Work hardor5PPT课件2.借助介词借助介词with 或或without来转换。来转换。例如例如:If you help me,Ill finish my job soon.-,Ill finish my job soon.如果你帮我，我将很快完成我的工作。如果你帮我，我
6、将很快完成我的工作。If there is no water,fish may die.Fish may die -.如果没有水，鱼可能会死。如果没有水，鱼可能会死。With your helpwithout water6PPT课件 注意事项注意事项 1.在在if引导的条件状语从句中，当主句是一般将引导的条件状语从句中，当主句是一般将来时时，不能够使用来时时，不能够使用be going to结构，而要用结构，而要用will。例如：例如：Ill help you with your English if I am free tomorrow.如果明天我有空，我会帮你学英如果明天我有空，我会帮你学
7、英语。语。2.在在if引导的条件状语从句中不能够使用引导的条件状语从句中不能够使用some，而要用而要用any。例如：例如：If you have any questions to ask,please come to my office.如果你有问题要问的如果你有问题要问的话，请到我办公室来。话，请到我办公室来。7PPT课件If 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.whe
8、ther1.if 在句中的含义不同在句中的含义不同8PPT课件2.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 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；引导的条件状语从句放于句首时多用逗号隔开；而而
9、if引导的宾语从句则不能。引导的宾语从句则不能。9PPT课件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 both will get good results.10PPT课件3.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 wa
10、nt to know if there a sports meeting next month.doesnt rainwill be2.If it ,well hold it.If 引导的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；11PPT课件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 I
11、f your mother_(buy)the book for you,it will be good for your study.dont understand copy doesnt get buys12PPT课件5.If you _(not work)hard,you _(not pass)the exam.6.If she _(mend)the computer,her father _(not blame).7.If your brother _(break)the window,he will feel very sorry for that.8.If the computer
12、(not work),mend it please.dont workwont passmendswont blame breaksdoesnt work13PPT课件9.If she _(not be)interested in math,she will find it very boring.10.If you _(get)high scores,your parents will be proud of you.11.If you _(be)happy,we will be happy.12.If she (translate)the sentence word by word,she
13、 _(get)its true meaning.isnt getaretranslates will get14PPT课件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 goAD15PPT课件16PPT课件
