97状语从句讲解

状语从句定义：在复合句中由从句表示的状语称作状语从句，它可以用来修饰谓语（包括非谓语动词）、定语或状语，或是整个句子。九类状语从句相关的连词一、时间状语从句二、条件状语从句三、比较状语从句四、结果状语从句五、原因状语从句六、目的状语从句七、让步状语从句八、地点状语从句九、方式状语从句when,while,before,after,until,sinceif,unlessas…as,notas/so…as…,…than…so…that…,such…that…Because,as,forsothatevenif/though,though/althoughwhere/whereverasif,asthough1.时间状语从句：引导时间状语从句的从属连词有：when,while,as,whenever,before,after,since,till,until,assoonas,once…等。如：Whenhewasstillayoungman,hewasforcedtoleavehishomelandforpoliticalreasons.Ithasbeen15yearssinceheleft.I’lltellhimthenewsassoonasIseehim.Onceyouhavegotusedtoit,youwilllikeit.注意：（1）when,as,whilewhen既可引导持续性动作，又可引导短暂性动作。它可以表示主句的动作和从句的动作同时发生，或从句的动作发生在主句动作之前。如：WhenIwasaboy,IusedtogototheseashoreonSundays.（同时）Whenthelessonwasover,webeganourwriting.（从句动作在前）As常引导持续性动作，侧重主句和从句的动作同时发生。Hehurriedhome,lookingbehindashewent.Hesangashewalked.While：指的是“在某一时间里”，“在…期间”，从句里的动作必须是持续性的，它强调主句和从句动作的同时发生。如：WhilehewasinLondon,hestudiedmusic.WhilewewerewatchingTV,hewaswritingacomposition.While也可做并列连词，表示对照的意思。如：Heistallwhilehisbrotherisshort.当when,as,while表示“在…一段时间里”，主从句的动作同时发生时，可以换用。如：While(When或As)wewerediscussing,Mr.Smithcamein.（2）如果when和before引导的从句位于主句之后，有时不能译成“当…时候”和“在…之前”，而要译成“就”、“才”、“这时”等。如：ThestrugglelastedfouryearsbeforetheNorthwonintheend.(3)bythetime,eachtime,everytime,immediately,themoment,theinstant,theminute,soonafter,shortlyafter都可以作为连词，引导时间状语。如：Eachtimehecame,hewouldcallonme.Youmustshowhiminimmediatelyhecomes.IrecognizedhimthemomentIsawhim.Bythetimehewasfourteen,hehadtaughthimselfadvancedmathematics.(4)till和until①如果主句谓语动词是持续动词，通常用肯定式的主句，表示“直到…为止”。如：Iworkedtill(until)hecameback.②如果主句谓语动词是瞬间动词，则用否定式的主句表示“直到…才”。如：Ididn’tgotobeduntil(till)hecameback.③放在句首表示强调时一般用until。如：Untilhereturns,nothingcanbedone.（5）时间状语从句中谓语动词不能用任何一种将来时，只能用现在时和过去时表示将来时。2.地点状语从句：通常由连词where和wherever引导,如：Gobackwhereyoucamefrom.Whereveryougo,youmustwritetoyourparents.Wherethereisawill,thereisaway.3.原因状语从句：通常由连词：because,as,since,nowthat引导。区别是:because：表示“因为”，直接而明确的原因和理由，语气最强，why提问的句子一般都用because回答。Hedidn’tcomebecausehewasill.since：表示“既然”，语气比because弱。Sinceyouarehere,youmustdoit.as：表示“因为”语气比because弱，引导从句可放主句前也可放主句后。Youneedn’tgowithme,asyouarebusy.AsIwasafraid,Ihidmyself.nowthat意思与since相似，表示“既然”。Nowthatalltheguestshavearrived,let’shaveourdinner.注意：①在强调句中强调原因状语从句，只能用because引导，不可用as或since，如：Itwasbecausehewasillthathedidn’tgowithus.②because可以引导表语从句,而as,since不可以.It’sbecauseheistoolazy.③for也表示“因为”，语气比较强。Itmustbemorning,forthebirdsaresinging.4.目的状语从句：通常由that,sothat,inorderthat,lest,incase（以防、免得）等引导：Hegotupearlyinorderthathecouldcatchtheearlybus.Shemarriedhimsothatshemighttendandcomforthim.Iexplainedagainandagainincaseheshouldmisunderstandme.Youshouldbringadictionaryincaseyoushouldneedit.Schoolwasclosedearlyinorderthatthechildrenmightgohomeaheadofthestorm.5.结果状语从句：由so…that,such…that等引导：Itwasverycold,sothattheriverfroze.Thereweresomanypeople(=suchalotofpeople)intheroomthatwecouldnotgetin.Hemadesuchanexcellentspeechthateveryoneadmiredhim.Theforeignvisitorwassuchafastspeakerthatnobodycouldunderstandhim.Hewassoangrythathecouldn’tspeak.Hegotsolittlepaythathisfamilyhadtoliveonwelfaremoney.6.条件状语从句:由if,unless,aslongas(=solongas)(只要),等引导：Ifplasticsandrubberareburned,theywillgiveoffpoisonousgases.Unlessyouworkhard,youwillfail.Youcangoout,aslongas(solongas)youpromisetobebackbeforeeleven.注意：条件状语从句中的谓语动词的时态不可用将来时，只能用现在时态或过去时态表示将来时。7.方式状语从句：由连词：as,asif,asthough引导：Theteachertoldthestudentstodoashedid.Leaveitasitis.Heheardanoise,asifsomeonewerebreathing.asif和asthough意义和用法大致一样，引导的从句多用虚拟语气，但也可用陈述语气。HetreatsmeasifIwerehisownson.Hewalkedasifhewasdrunk.8.比较状语从句：由连词as…as,notso(as)…as,than等引导：Ithinkitwasasgoodastheoneyoulentme.Noonecanbemorefitforhisofficethanheis.Hecan’trunsofastasshe.注意：“the+比较级(接从句)，the+比较级(接主句)，这一句型也归在比较状语从句内。如：Themoreyoustudy,themoreyouknow.Theharderwework,thehappierwefeel.9.让步状语从句：由though,although,as,evenif,eventhough,wh-ever,nomatter-wh,whether引导.whateverwhoeverwhicheverwheneverwhereverhoweverwh-evernomatterwhonomatterwhatnomatterwhichnomatterwhennomatterwherenomatterhownomatterwh-Whenever(=nomatterwhen)youcallonme,youarealwayswelcome.Wherever(nomatterwhere)youwork,youcanalwaysfindtimetostudy.Taketheoneyoulikebest,whichever(nomatterwhich)itis.NomatterwhatIsayorhowIsayit,healwaysthinksI’mwrong.Whetherhecomesornot,we’lldiscusstheproblemthisafternoon.注意：（1）让步状语从句在句中的位置可放前也可放后，有时还可以插在主句中间。（2）though与although同义，用法基本一样，前者通俗，口语化；后者较正式，多放于句首，不能与but连用，但可以与yet,still等连用，用来加强语气。Though(Although)hewastired,yet(still)hewentonworking.（3）as引导让步状语从句时从句部分语序要部分倒装。如：Youngasheis,hecanreadandwriteinseveralforeignlanguage.Childashewas,hehadtosupportthefamily.Surroundedaswewerebytheenemy,wemanagedtomarchforward.