状语从句状语从句在句中作状语，可分为：时间、条件、让步、原因、目的、成果、比较、地点、方式状语从句。一、时间状语从句引导时间状语从句的连词有：when,as,while,until,not…until,before,after,since,theminute,themoment,each(every,next,thefirst)time等。时间状语从句中一般用一般目前时或一般过去时。1.when,while,as都可解释为“当```的时候”但侧重点有所不一样。(1)whenEg:WhenIarrivedhome,Ihadalittlerest.注意：when从句的主语与主句主语相似，谓语动词是be动词时，从句主语和be可以省略。Eg:When(shewas)walkingalongthestreet,shemetherclassteacher.(2)as除了表达“当```的时候”，还可表达为“一面```一面”，“伴随”Eg:Hesangashedanced.(一面```一面)Youwillgrowwiserasyougrowolder.(伴随)(3)while表达“当...的时候”强调主句的动作和从句的动作同步发生，从句一般用进行时，从句动词必须是延续性动词。Eg:Whilewewereworking,theywerehavingarest.While(theywere)havingadiscussion,theygotveryconfused.注意：while有对比的含义，解释为“然而”。Eg:Ipreferblacktee,whilehelikescoffee.2.until,not…until表达“直到```才”，在肯定句中主句常用延续性动词；在否认句中主句常用短暂性动词。肯定句：Iwaiteduntilmidnight.否认句：Ididnotleaveuntilmidnight.注意(1)notuntil…在句首，主句用倒装Eg:NotuntilyouhadexplainedhowdidImanagetodoit.(2)Itisnotuntil…that…引导的强调句Eg:Itwasnotuntilitwasdarkthathecameback.3.theminute,themoment,eachtime都可表达“一```就```”Eg:Theworkerrecognizedthetypeofthemachinethemomenthesawit.注意：theminute,themoment,each(every,next,thefirst)time作连词不和when连用。4．Hardly/scarcely…when,nosooner…than,assoonas表达为“一```就```”Eg:Ihadhardly/scarcelygothomewhenitbegantorain.Ihadnosoonergothomethanitbegantorain.ItbegantorainassoonasIgothome.注意：Hardly/Scarcely…when,nosooner…than位于句首，主句用倒装Eg:HadIhardly/scarcelygothomewhenitbegantorain.NosoonerhadIgothomethanitbegantorain.二、条件状语从句条件状语从句分为两大类：真实条件句和虚拟条件句。引导条件状语从句的连词有：if,evenif/though,unless/if…not,aslongas/solongas,asfaras/sofaras,provided/providing(that),onconditionthat等。条件状语从句中假如主句是未来时，条件状语从句用一般目前时。1.unless和if…notunless相称于if…notEg:Youwillfailunlessyoustudyhard.Youwillnotfailifyoustudyhard.注意：在虚拟条件句中可用if…not，但不能用unlessEg:Ifshewerenottoosilly,shewouldunderstand.2.引导条件状语从句的其他连词：Eg:Youmaygothere,aslongasyoukeepquite.Eg:Ishallgiveyouthebookonconditionthatyoureturnittomorrow.Eg:Iwillgoprovidedthatyougotoo.三、让步状语从句引导让步状语从句的连词有：though,although,evenif/though,however,nomatterhow,nomatterwhat,nomatterwho等。1.though,although不可与but连用，但可以和yet,still连用.Eg:Though/Althoughitisraining,theyarestillrunningoutside.注意：(1)though可引导倒装(although不引导倒装)，构造为：强调对象+as/though+主语+其他成分【强调对象可为表语（名词、形容词）或状语（副词），表语为名词时，前面不用冠词。】Eg:Childas/thoughhewas,heknewwhatwastherightthingtodo.Tiredasheis,hegoesonwithhiswork.2.despite和inspiteof也有让步意义，后接名词或动词，而though,although是连词，后接从句。Eg:Despite/Inspiteofwantingtoseehimagain,sherefusedtoreplytohisletter.Though/Althoughshewantedtoseehimagain,sherefusedtoreplytohisletter.3.“nomatter+疑问词”或“疑问词+后缀ever”Eg:Nomatterwhathappened,hewouldnotmind.Whateverhappened,hewouldnotmind.注意：nomatter+疑问词不能引导名词性从句4.evenif/though表达“虽然”Eg:Hedoesn’twanttomarryherevenif/thoughhelovesherverymuch.四、原因...
