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《Unit 4 Dealing with problem Lesson 1 Problem page--if unless引导条件状语从句.ppt》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。
1、条件状语从句引导词：if和unless1.真实条件句表示的情况有可能发生，用陈述语气。 IwillnotgotothepartyifIamnotinvited.2.虚拟条件句表示的情况不可能发生或者发生的可能很小。下面我们重点讲虚拟条件句If引导的条件状语从句31.与现在事实相反IfIknewhistelephonenumber,Iwouldtellyou.IfIwereyou,Iwouldnotsoproud.2.与过去事实相反1.Ifhehadtakenmyadvice,hewouldnothavemadesuchamistake.2.IfIhadgotthereearlier
2、,Iwouldhavemether.3.与将来的事实相反1.IftherewereaheavysnownextSunday,wewouldnotgoskating.2.Ifsheshouldcome,Iwouldtellheraboutthematter.1.Ifmybrotherwerehere,everythingwouldbeallright. 2.Ifyouhadworkedhard,youwouldhavepassedtheexam. 3.Ifitshouldraintomorrow,wewouldnotgocamping.Moreexamples如果条件从句中有we
3、re/had/should时，可以把if省略，把这几个词放到主句之前，构成主谓倒装。WereIyou(=IfIwereyou),Iwouldnotdoit.HadIthetime(=IfIhadthetime),Iwouldgo.Shouldyouchangeyourmind(=Ifyoushouldchangeyourmind),noonewouldblameyou.当条件状语从句表示的行为所发生的时间和主句表示的行为所发生的时间不一致时，被称为“错综时间条件句”，动词的形式要根据它所表示的时间作相应的调整。Ifyouhadfollowedmyadvice,youwouldbeb
4、etternow.Ifyouhadnotstudiedtheproblemcarefully,youwouldfinddifficultynow.一般情况下，unless相当于if…not，可以互换。用一般现在时代替将来时。Iwon´tletyouinunlessyoushowmeyourpass=Iwon´tletyouinifyoudon´tshowmeyourpass.如果你不出示通行证，我就不让你进来。unless引导的条件状语从句如果主句描述的是情感或情绪活动方面的内容，if…not结构不能换成unless。如：I´llbequitegladifshedoesn´tcom
5、ethisevening.(她今晚如果不来我很高兴。Unlessyou take more care, you’ll have an accident.(如果不多加小心的话，你会出事故的。)DosomeexercisesTheprinterisofgoodquality.Ifit_____breakdownwithinthefirstyear,wewouldrepairitatourexpense.A.wouldB.shouldC.couldD.might2._____,theforestfirewouldhavebeendiscoveredmuchearlier. A.Butf
6、ortheircare B.Iftheywerecareful C.Withouttheircare D.Hadtheybeenmorecareful3.Ifthepresentunemployment______continue,thesocietywouldfaceamoredifficultsituation. A.would B.should C.might D.could4.—Theweatherhasbeenveryhotanddry. —Yes.Ifithadrainedevenadrop,thingswouldbemuchbetternow!Andmyvegetab
7、les____. A.wouldn’tdie B.didn’tdie C.hadn’tdied D.wouldn’thavedied5.HadIknownaboutthecomputerprogram,ahugeamountoftimeandenergy_____. A.wouldhavebeensaved B.hadbeensaved C.willbesaved D.wassaved6.Ifwe____theotherroad,wemighthavearrived
