22条件状语从句PPT课件

grammarConditionalclauses引导条件状语从句的连接词主要有：if(如果)、unless(除非)或aslongas(只要)等。条件状语从句引导条件状语从句最常用的连词是if。如果你请他帮忙,他会帮你的。Ifyouaskhim,hewillhelpyou.如果你考试不及格,你会让他失望的。Ifyoufailintheexam,youwilllethimdown.如果你作业做完了就可以回家了。Ifyouhavefinishedthehomework，youcangohome.条件状语从句unless=if...not.除非,若不,除非下雨,比赛将照常进行。Unlessitrains,thegamewillbeplayed.Ifitdoesn’train,thegamewillbeplayed.让我们出去散步吧，除非你太累了。Let'sgooutforawalkunlessyouaretootired.Ifyouarenottootired,let'sgooutforawalk.条件状语从句•1.除非你早点动身，你就不能及时赶到那儿。•Youwillfailtoarrivethereintimeunlessyoustartearlier．•Youwillfailtoarrivethereintimeifyoudon’tstartearlier．•2.除非天气不好，我每天早晨都要去慢跑。•Unlessbadweatherstopsme，Igojoggingeverymorning．•Ifbadweatherdoesn’tstopme，Igojoggingeverymorning．•3.除非你需要，我不会借钱给你的。•Iwon’tlendyoumoneyunlessyouareinneed．•Iwon’tlendyoumoneyifyouarenotinneed．3、so/aslongas只要只要你保持书的清洁，你就可以把我的书借去。Youmayborrowmybookas/solongasyoukeepitclean.只要你高兴，你做什么都没有关系。So/Aslongasyou'rehappy,itdoesn'tmatterwhatyoudo.只要你努力，你就会成功。You’llsucceedas(so)longasyoutryhard.条件状语从句时态问题在条件状语从句中，要注意主将从现的规定，即主句用一般将来时，从句用一般现在时表示将来时。我有时间，我就来看你。IwillcometoseeyouifIhavetime.条件状语从句If从句（一般现在时），主句（一般现在时）•表示科学常识，经常性的动作•1.如果水被加热，它会变成蒸汽。•Ifwaterisheated,itturnstosteam.•2.如果我需要理发，我通常去我家附近的理发店。•IfIneedahaircut,Iusuallygotothebarber’snearwhereIlive.•3.如果天下雨，人们通常星期天不出门。•Peopleoftendon’tgooutonSundaysifitrains.表示将来的可能性时，运用“主将从现”的原则。•1.如果我得到这项工作，我将会买个手机。•IfIgetthejob,I’llbuyamobilephone.•如果我的家庭作业很难，我会叫Helen帮助我。•2.Ifmyhomeworkisdifficult,I’llaskHelentohelpme.•如果我今天下午有时间，我将去和同学踢足球。•3.IfIhavetimethisafternoon,I’llgotoplaysoccerwithmyclassmates.典型例题：Ifhe___inhalfanhour,we___waitforhim.A.won'tcome,won'tB.won'tcome,don'tC.doesn'tcome,won'tD.willcome,don't条件状语从句误区提醒if既可以引导条件状语从句，表示如果，也可以引导宾语从句，表达是否。辨别它在这两种从句中的时态是我们经常容易出错的地方。另外，if和unless的用法也需注意条件状语从句1.Ifit____tomorrow,we____toclimbmountains.A.doesn’train;goB.won’train;willgoC.won’train;goD.doesn’train;willgo2．—Doyouknowif________tomorrowmorning?—No.Iwillcallyouifshe________back.A.shewillcome;comesB.shecomes;willcomeC.willshecome;comesD.willshecome;willcome条件状语从句3．We’llgototheparkifit_____raintomorrow.A.don’tB.doesn’tC.won’t4．Wearenotsureifit____tomorrow.Ifit____,oursportsmeetingwillbeputoff.A.rains;rainsB.rains;willrainC.willrain;willrainD.willrain;rains条件状语从句5.I’llgivethebooktohimaslongashe___herenextSunday.A.willcomeB.comesC.iscomingD.came6.Youwillnotgetgoodgrades______youworkhard.A.andB.unlessC.ifD.aslongas条件状语从句•40.–WillyoupleasegivethedictionarytoJane?–Sure,I’llgiveittoher_______shearriveshere.A.beforeB.untilC.becauseD.assoonas37.Asnakebithim______hewenttoseeadoctoratonce.A.ifB.whereC.becauseD.so•28.Youwillbelateforschool________youdon’tgetupearly.A.butB.ifC.andD.or•34.Itwasrainingheavily,_____wedecidedtostayathomeandwatchTV.A.unlessB.ifC.becauseD.so•36.______thedinnerwasallover,everyonehelpedwashthedishes.A.aslongasB.WhenC.BeforeD.if