1、If引导条件状语从句引导条件状语从句潘店镇中学第1页例句例句:If people obey the traffic rules,there will be fewer accidents.if引导条件状语从句引导条件状语从句if:隶属连词,意思是:隶属连词,意思是:“假如,假如,倘若假如,假如,倘若”从句从句主句主句T There here willwill be be fewer accidentsfewer accidents if if people obey the traffic rulespeople obey the traffic rules.原句可改为:原句可改为:if引导条
2、件状语从句既能够放在句子前,引导条件状语从句既能够放在句子前,也能够放在句子后。也能够放在句子后。从句位于主句之前时,惯用逗号将其与主句隔开从句位于主句之前时,惯用逗号将其与主句隔开。结构结构:第2页主句谓语中也能够含有情态动词,主句谓语中也能够含有情态动词,如:如:must,can,could,should等等时态时态:if引导条件状语从句,引导条件状语从句,主句用普通未来时(主句用普通未来时(will),从句用普通现在时。从句用普通现在时。例句例句:If people obey the traffic rules,there will be fewer accidents.主句谓语中也能够
3、用主句谓语中也能够用had better(not)do,提提议提提议例句例句:假如交通指示灯是红,你必须停下来等一等。假如交通指示灯是红,你必须停下来等一等。eg:Ifthetrafficlightsarered,youmuststopandwait.例句:假如你想减肥,你最好锻炼。例句:假如你想减肥,你最好锻炼。eg:Ifyouwanttoloseweight,youhadbettertakesomeexercise.第3页if反义词:反义词:if.not.=unless,意思是:意思是:“假如不,除非假如不,除非”I wont go there unless I hear from you
4、.(同义句同义句)I wont go there _ I _hear from you.if dont I wont go to the party if I am not invited.(同义句同义句)I wont go to the party_ I am invited.unless第4页变换:变换:1.有有if引导条件状语从句复合句中,当主句和从句引导条件状语从句复合句中,当主句和从句主语均为主语均为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,祈使句,or+简单句简单句”You can pass the exam if you work har
5、d.-,and you will pass the exam.If you dont hurry up,you will be late again.Hurry up,-you will be late again.Workhardor第5页2.借助介词借助介词with 或或without来转换。来转换。比如比如:If you help me,Ill finish my job soon.-,Ill finish my job soon.假如你帮我,我将很快完成我工作。假如你帮我,我将很快完成我工作。If there is no water,fish may die.Fish may die
6、-.假如没有水,鱼可能会死。假如没有水,鱼可能会死。Withyourhelpwithoutwater第6页注意事项注意事项 1.在在if引导条件状语从句中,当主句是普通未来引导条件状语从句中,当主句是普通未来时时,不能够使用时时,不能够使用be going to结构,而要用结构,而要用will。比如:比如:Ill help you with your English if I am free tomorrow.假如明天我有空,我会帮你学英假如明天我有空,我会帮你学英语。语。2.在在if引导条件状语从句中不能够使用引导条件状语从句中不能够使用some,而,而要用要用any。比如:比如:If yo
7、u have any questions to ask,please come to my office.假如你有问题要问话,假如你有问题要问话,请到我办公室来。请到我办公室来。第7页if 引引导条件状条件状语从句和从句和if 引引导宾语从句区分从句区分: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“假如假如”Ill go to see you if I am free next week.I want to know if he is a teacher.whether1.if 在句中含义不一样在句中含义不一样第8页2.if 在从句
8、中位置不一样在从句中位置不一样If 引导宾语从句放在主句之后;而引导宾语从句放在主句之后;而if引导引导状语从句可放在主句之前也可放在主句之状语从句可放在主句之前也可放在主句之后后=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 引导条件状语从句放于句首时多用逗号隔开;引导条件状语从句放于句首时多用逗号隔开;而而if引导宾语从句则不能。引导宾语从句则不能。第9页找出以下句子中哪些是找出以下句子中哪些是
9、if条件状条件状语从句,从句,哪些是哪些是if宾语从句从句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.第10页3.时态要求上有区分时态要求上有区分If 引导条件状语从句时态为普通现在时引导条件状语从句时态为普通现在时 记记住住“主将从现主将从现”1.I want to
10、know if there a sports meeting next month.doesnt rainwill be2.If it ,well hold it.If 引导宾语从句时态由主句及本身时态决引导宾语从句时态由主句及本身时态决定;定;第11页If 引引导条件状条件状语从句从句练习1 If I _(not understand),I will ask my teacher for help.2If I _(copy)your homework,I will cheat myself.3 If she _(not get)up early,shell miss the early bu
11、s.4 If your mother_(buy)the book for you,it will be good for your study.dont understand copy doesnt get buys第12页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 compute
12、r (not work),mend it please.dont workwont passmendswont blame breaksdoesnt work第13页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 get第14页1.Ifyou_totheparty,youllhaveagreattime.A.willgoB.wentC.goD.going2I_hertheanswerifshe_me.A.cantell,willaskB.willtell,willaskC.wouldtell,askD.willtell,asksCD3.Whatareyougoingtodotomorrow?-Wellgotothelibrarytomorrowifit_.A.isntrainB.rainC.wontrainD.doesntrain4.Whatwillyoudoifyou_totheoldfolkshomevisit?A.goB.wentC.goingD.willgoAD第15页第16页