34状语从句

状语从句定义状语从句在句中作状语,修饰主句中的动词,形容词或副词等.状语从句放在主句之前时,常用逗号分开;放在主句之后,一般不用逗号.状语从句按其意义和作用,可分为9种.时间状语从句条件状语从句原因状语从句地点状语从句让步状语从句目的状语从句结果状语从句方式状语从句比较状语从句一.时间状语从句1.常用连词:when,while,as,before,after,since,until,assoonas,everytime,eachtime,themoment,bythetime,immediately,theminute,thesecond,hardly…when,nosooner…than2.时间状语从句一般不用将来时,主句若为将来时,从句要用一般时(主将从现).IwillgoonwiththeworkwhenIcomebacktomorrow.3.连词when,while,as均可表示“当…的时候”,但有区别.*as多用在口语中,强调“同一时间”或“一前一后”,有时还有“随着”的含义.1.Ashewaseatinghisbreakfast,heheardthedoorbellring.(强调同一时间)2.AsIwasgoingout,itbegantorain.(强调两个动作紧接着先后发生)3.Asspringwarmsthegoodearth,allflowersbegintobloom.(随着)*When强调“特定时间”1.Whenspringcame,hefeltlikeatrip.2.WhenIwascleaningmyroom,thephonerang.Attentionbedoing,beabouttodo,be+介词短语,when(正在这个时候)Examples1.Thestudentsweredoingtheirhomeworkwhentheteachercamein.2.Iwasabouttogooutwhenthephonerang.3.Theywereintheplanewhenitcrashed.*While表示的时间是一段,而不是一点.后面接的动词是持续性动词.Whilehewaseatinghisbreakfast,heheardthedoorbellring.*While还可以表示对比,意为“而”.Iwasreadingwhilehewasplaying.*While还可以表示“尽管”,放句首.Whilewhattheteachersaidwasright,hewouldnotlisten.=although/though4.表示“一…就…”的连词assoonas,instantly,immediately,directly,themoment,theminute,theinstant,thesecond…AssoonasIfinishthework,I’llgotoseeyou.Themomenthecamein,thephonerang.5.nosooner…than/hardly…when/scarcely…when引导的从句表示“刚…就…”.*主句中的动词一般用过去完成时,从句用过去时.*若把nosooner,hardly,scarcely提到句首,主句要用部分倒装.Examples1.IhadhardlyenteredtheroomwhenIheardaloudnoise.2.NosoonerhadIenteredtheroomthanIheardaloudnoise.6.by+时间:表示“到…为止已经”*Bytheendoflastyear,wehadlearnt2,000Englishwords.*Bytheendofnextyear,wewillhavelearnt2,000Englishwords.*Theyhavefinishedtheirtasksbynow.7.before的用法及含义①多久之后才…Itwillbe+一段时间+before+现在时*Itwillbe10yearsbeforewemeetagain.②不久之后就…Itwon’tbelongbefore+现在时Itwon’tbelongbeforetheymeetagain.③还来不及就…常与could连用ThephonestoppedringingbeforeIcouldanswerit.试比较Itisalmostfiveyearssincewesaweachotherlasttime.Itwillbefiveyearsbeforewemeeteachother.二.原因状语从句1.常用连词:because,since,as,for,nowthatseeingthat,consideringthat,inthat*because表示直接的原因或理由,着重点在从句,用于回答why.---WhyisJimabsenttoday?---Becauseheisill.2.because,since,as,for的区别有时,for引起的从句并不表示原因,而是表示一种推断或解释.*for引导的从句并不说明主句行为发生的直接原因,只是提供一些补充说明,且不可位于主句前.Thedayswerelong,foritwasJuly.Thedaybreaks,forthebirdsaresinging.*since一般表示对方已知的,无须加以说明的既成事实的理由,全句中心在主句.Sinceyouareill,Iwillgoalone.*as表示十分明显的原因,一般说明因果关系,着重点在主句.Asitissnowing,weshallnotgotothepark.*as和since的差别不大,通常位于主句前.三.地点状语从句1.常用连词where,wherever,anywhere,everywhere•Putitwhereyoucanseeit.•Iwillfindhim,whereverheis.•Youcan’tcampanywhere/whereveryoulikethesedays.Attention*不要和where引导的定语从句相混淆.where*Weshallgo_____wearemostneeded.*Thisistheplace_______Ilived5yearsago.where(where引导地点状语从句)(where引导定语从句，修饰theplace)四.条件状语从句1.常用连词if,unless,onconditionthat,provided(that),providing(that),as/solongas,suppose(that),supposing(that),incase*如果主句是将来时,条件状语从句用一般现在时表示.(主将从现)*Ifitrainstomorrow,themeetingwillbeputoff.*IshallnotgotothecinemaunlessIfinishmyhomeworkbeforeeight.*SupposingthatIdon’thaveadayoff,whatshallwedo?五.让步状语从句1.由although/though,evenif/though引导.Although/ThoughIdidn’tknowanybodyattheparty,Ihadaverygoodtime.注意:although/though引导从句时,主句不用but,但可用yet.2.由though或as引导的倒装句中.Childasheis,heknowsalot.=Childthoughheis,heknowsalot.=Although/Thoughheisachild,heknowsalot.注意:as引导的让步状语从句的表语是名词时,名词前置不加冠词.Examples*Boyashewas,hehadtomakealiving.*Patientashewas,hewasunwillingtowaitthreehours.*Hardashetried,hefailedtopasstheexam.*Tryashemay,hewillfailagain.3.由whatever,whenever,wherever,whoever,whichever和however引导,相当于nomatterwhat(when,where,who,which,how).①Whatever(Nomatterwhat)happens,weshallneverlosehope.②However(Nomatterhow)latehegoesbackhome,hismotherwillwaitforhim.Attention疑问词+ever既可引导让步状语从句,也可以引导名词性从句.Whoeverbreaksthelawwillbepunished.Nomatterwho/Whoeverbreaksthelaw,hewillbepunished.nomatter+疑问词只能引导让步状语从句.六.目的状语从句常用连词sothat,inorderthat,lest,forfearthat1.Theystartedearlysothattheymightarriveintime.2.Heworkshardinorderthathecanservehiscountrywell.3.Ididn’tmentionitforfearthathecry.七.结果状语从句常用连词so,sothat,so…that,such…that1.Theboxissoheavythatnobodycanmoveit.=Itissuchaheavyboxthatnobodycanmoveit.2.Hemadeawrongdecision,sothathalfofhislifetimewaswasted.注意:sothat既可引导目的状语从句,又可引导结果状语从句,其区别在于:引导结果状语从句时通常用逗号同主句分开.Attentionsuch/so…that引导的结果状语从句与such/so…as引导的定语从句的区别.1.Itissuchabigstone______noonecanlift.2.Itissuchabigstone______noonecanliftit.asthat(定语从句)(结果状语从句)八.方式状语从句常用连词as,justas,asif,asthough,intheway(that)1.Hewatchedherasacatwatchedarat.2.Theoldmanrunsveryfastasifhewereayoungman.九.比较状语从句常用连词as…as,than,notso…as…,the+比较级…the+比较级1.HespeaksEnglishaswellasyou.2.Iknowyoubetterthanhedoes.3.Themorewepractise,thebetterourEnglishwillbe.