1、If 引导的条件引导的条件状语从句状语从句 一一、定义、定义二二、具体用法、具体用法三三、练习、练习四四、拓展、拓展五、总结五、总结目录:目录:定义:定义:if“如果如果,假如假如”它引导的句子表示某事发生它引导的句子表示某事发生所需的条件,即所需的条件,即“在在条件下,某事才能发生条件下,某事才能发生”,在,在句子中充当状语,因此称之为条件状语从句句子中充当状语,因此称之为条件状语从句。(If引导的条件状语从句表示假如有从句的动作发引导的条件状语从句表示假如有从句的动作发生,就会有主句动作的发生生,就会有主句动作的发生)一、什么是条件状语从句?一、什么是条件状语从句?位置位置:从句可放在主句
2、之前或之后,但是放在主从句可放在主句之前或之后,但是放在主句之前须有逗号隔开句之前须有逗号隔开eg:如果我有足够的钱,我就去环游世界如果我有足够的钱,我就去环游世界If I have enough money,I will travel around the world=I will travel around the world if I have enough moneyIfitrainstomorrow,Iwillstayathome.从句从句主句主句二、条件二、条件状语状语从句的用法从句的用法IfIgetuplate,Iwillbelateforschool.IfIdontfinish
3、myhomework,Iwontgotobed.Ifyoujointheband(乐队乐队),youwillbefamous.Letslookatsomesentencesfirst用法用法1:If条件句条件句:条件句用于陈述语气,表示将来的可能性,能力,条件句用于陈述语气,表示将来的可能性,能力,允诺,命令,要求,请求,建议时,假设的情况可能发生,允诺,命令,要求,请求,建议时,假设的情况可能发生,其中其中 if if 是是“假如,如果假如,如果”的意思。的意思。主句主句一般将来时一般将来时 ,从句用从句用一般现在时一般现在时。“主将从现主将从现”的原则。的原则。构构成成条件从句条件从句主句
4、主句时态If一般一般现在在时主主语shall/will+动词原形原形例例句句Ifhecomes,hewilltakeustothezoo.用法用法2:如果如果主句含有主句含有must,may,can等情态动词,从句也要用等情态动词,从句也要用一般一般现在时现在时。Youmuststopifthetrafficisred.如果是如果是红灯,你必需停下来。灯,你必需停下来。Ifyoufinishthehomework,youcangohome如果你作业做完了就可以回家了如果你作业做完了就可以回家了。Ifyouwanttoloseweight,youmust/shouldeatlessbread.如
5、果如果你想减肥,你必须少吃面包。你想减肥,你必须少吃面包。用法用法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。Dontgoandplayfootballifyoudontfinishyourhomework.如果没有完成家庭作如果没有完成家庭作业,就不要去踢足球。,就不要去踢足球。PleasecallmeifhecomesnextSunday.如果他下周日来的如果他下周日来的话,请打打电话给我。我。用法用法4:表示科学常识、事实、表示科学常识、事实、经常性的动作或倾向经常性的动作或倾向自动会发生的自动会发生的事事If If 从句从句 (一般现在时),
6、主句(一般现在时),主句 (一般现在时一般现在时 )。)。1.If water 1.If water is heatedis heated,it,it turnsturns to steam.to steam.如果水加热,就会蒸发。如果水加热,就会蒸发。2.If people 2.If people dont getdont get enough sleep,their thinking ability enough sleep,their thinking ability is is reducedreduced.如果人们睡眠不足,他们的思维能力就会下降。如果人们睡眠不足,他们的思维能力就会
7、下降。3.If I 3.If I needneed a haircut,I a haircut,I usuallyusually gogo to the barbers near my to the barbers near my house.house.如果我要剪头发,我通常是去附近那一家理发店。如果我要剪头发,我通常是去附近那一家理发店。4.People 4.People often often dont godont go out on Sundays if it out on Sundays if it rainsrains.如果周日下雨的话,人们一般不出门。如果周日下雨的话,人们一般
8、不出门。三、练一练三、练一练:1。如果她早点儿起床,就有时间在家里吃早餐。如果她早点儿起床,就有时间在家里吃早餐 If she_ _a little earlier,shell have time to eat breakfast at home.2。如果你参加聚会,你将会过得很开心。如果你参加聚会,你将会过得很开心。If you_ the party,you_ _ a great time.3。如果明天下雨,我们将不去野餐。如果明天下雨,我们将不去野餐If it _tomorrow,we _ _ for a picnic.4。如果你经常听英文歌,你将会喜欢英语。如果你经常听英文歌,你将会喜欢
9、英语If you often _ _English songs,you_ _English.getsupjoinwillhaverainswontgolistentowilllike1.Ifhe_(not,do)it,I_(do)it.2.Ifyou_(be)lateforschool,myteacher_(be)angry.arewillbe3.Ifshe_(win)theprize,we_(be)happy.winswillbe4.IfI_(not,eat)somuch,I_(get)thinner.5.Ifyou_(tell)them,they_(not,believe)you.dont
10、eatwillgettellwontbelievedoesntdowilldo用所给单词的正确形式填空:用所给单词的正确形式填空:6I_(stay)athomeifit_(rain).7.Ifit_(not,rain),I_(go)out.8.we_(play)footballifitis_(sun).9.Ifshe_(become)astar,herparents_(be)proudofher.10.He_(watch)TVifhe_(be)free.willstayrainsdoesntrainwillgowillplaysunnybecomeswillbewillwatchis四、拓展四
11、、拓展除了除了if之外,是否还有其他连词可以引之外,是否还有其他连词可以引导条件状语从句呢?导条件状语从句呢?最常见的还有:最常见的还有:so/as long as只要只要 unless除非,若不除非,若不1.as(so)long as.“1.as(so)long as.“只要只要,就就 ”表示表示 一种前提一种前提条件条件Youll succeed Youll succeed Youll succeed Youll succeed as(so)long as(if only)as(so)long as(if only)as(so)long as(if only)as(so)long as(i
12、f only)you try hard.you try hard.you try hard.you try hard.只要你努力,你就会成功。只要你努力,你就会成功。只要你努力,你就会成功。只要你努力,你就会成功。As long as you are happy,it doesnt matter what you do.As long as you are happy,it doesnt matter what you do.As long as you are happy,it doesnt matter what you do.As long as you are happy,it doe
13、snt matter what you do.只要你高兴,你做什么都没有关系只要你高兴,你做什么都没有关系只要你高兴,你做什么都没有关系只要你高兴,你做什么都没有关系You may borrow my books as long as you keep it clean.You may borrow my books as long as you keep it clean.You may borrow my books as long as you keep it clean.You may borrow my books as long as you keep it clean.只要你保持
14、书的清洁,你就可以借我的书。只要你保持书的清洁,你就可以借我的书。只要你保持书的清洁,你就可以借我的书。只要你保持书的清洁,你就可以借我的书。2unless除非;若不;如果不除非;若不;如果不;除非在;除非在时候时候You will fail to arrive there in time You will fail to arrive there in time unless unless you start earlieryou start earlier如果你不早点动身,你就不能及时赶到那儿。如果你不早点动身,你就不能及时赶到那儿。UnlessUnless bad weather sto
15、ps me bad weather stops me,I go for a walk every morningI go for a walk every morning除非天气不好,我每天早晨都要去散步。除非天气不好,我每天早晨都要去散步。I wont loan you I wont loan you unlessunless you are in extreme need of money you are in extreme need of money若不是你急需用钱,我不会借钱给你的。若不是你急需用钱,我不会借钱给你的。中考真题:中考真题:(2011安徽)1.If the rain _
16、(stop)tonight,we will go to the cinema.(2012黑龙江)2.Ill buy a computer if I _(have)enoug money.(2013内蒙古)3.You _(not get)nervous if you _(do)enough exercise.(2014浙江)4.If she _(be)kind to me,I _(not argue)with her.stopshavewontgetdoiswontargue分析试题特点及做题思路:分析试题特点及做题思路:l1.考连词考连词-做题思路:做题思路:分析句子分析句子-判断关系判断关系
17、-选择正确的连词:选择正确的连词:1.Youwontgetnervous_youdoenoughexercise.A.if,B,unlessC,whether2._youhurryup,youwillmisstheearlybus.A.if,B,unlessC,whether分析试题特点及做题思路:分析试题特点及做题思路:2.Youmay_(pass)theexamifyou_(study)hard.2.考时态考时态-做题思路做题思路:认字认字-判断语境提供的时态特点判断语境提供的时态特点-选择正确的时态选择正确的时态A.rain,stayB.rains,stayC.rains,willsta
18、yD.rain,willstay1.IfIt_(rain)tomorrow,I_(stay)athome.A.pass,studyB.willpass,studyC.pass,willstudyD.passes,studyIfImill,_.IwillseeadoctorLookandsayIfImlate,_.Iwillsaysorry条件状语从句在日常生中的应用:条件状语从句在日常生中的应用:IfImhungry,Iwill_.IfImtired,Iwill_.LookandsayeatsomefoodhavearestIfitrainstomorrow,I_.willwatchTVathomeIfit_tomorrow,_.Illplaybasketballdoesntrainif条件句不一般条件句不一般,几个要点记心间几个要点记心间;条件句条件句,放在前放在前,逗号要放句中间。逗号要放句中间。条件句表可能,条件句表可能,主将从现不一般;主将从现不一般;条件句表事实,条件句表事实,主句常用现在时。主句常用现在时。五、五、Summary(小结)(小结)Ifwestudyharder,wewilldowellintheexams.Tryourbesttostudyharder!Homework.Finishtheexercisesintheworkbook.