英语中六大从句用法总结

英语中六大从句用法总结1.定语从句定语从句所修饰的先行词可以是名词或代词，也可以是一个句子。定语从句通常位于先行词之后，由关系代词或关系副词引导。关系词在从句中的成分修饰的先行词可否省略关系代词that主语或宾语人、物作宾语时可省略which主语或宾语物作宾语时可省略who、whom、whose主语、宾语和定语人作宾语时可省略关系副词when、where、why时间状语、地点状语、原因时间、地点、原因一般可省略*限制性定语从句限制性定语从句修饰先行词，对先行词起修饰作用，紧接先行词之后，无逗号，若省去，原句意思不完整。引导定语从句的关系代词有who,whom,whose,which,that等。who,whom,whose用于指人，whose有时也可指物，相当于ofwhich；which用于指物；that既可指人也可指物，但只用于限制性定语从句中。关系代词除了引导定语从句，替代先行词外，还在从句中担任主语、宾语、定语等。ThecomputersandcableswhichmakeuptheInternetareownedbypeopleandorganizations.Thosewholivealoneorwhoaresickmayhavetroubleingettingclosetootherpeople.Thegirlwhoseparentsdiedinanaccidentislivingwithhergrandmother.1)当先行词是all,anything,everything,something,nothing等不定代词或先行词前有first,last,any,few,much,some,no,only以及形容词最高级修饰时，只能用关系代词that引导从句。ThatisallthatI'veheardfromhim.He'sthefirstpersonthatI'mgoingtointerviewthisafternoon.2)关系代词的省略在从句中作宾语的关系代词常可省略。关系代词紧跟介词，作介词宾语时不可用that，只可用which或whom引导从句，并且不可省略，但当介词位于宾语从句句末时，作为介词宾语的关系代词仍可用that，也可省略。Thisisoneofthosethingswithwhichwehavetoputup.Thisisoneofthosethings(which\that)wehavetoputupwith.3)引导定语从句的关系副词有when,where,why等。关系副词在从句中作状语，意义上相当于一个“介词+which”的结构。Evenincomicbookswhere(=inwhich)therearenowords,thestoriesarefullyexpressedthroughthedrawings.Nooneknowsthereasonwhy(=forwhich)hewassoangrythatday.*非限制性定语从句非限制性定语从句既可修饰先行词，也可修饰整个主句，起补充说明作用，与主句之间有逗号隔开，若省去，原句意思不受影响。不可用that引导非限制性定语从句。关系词不可省略。Everyobjecthasagravitationalpull,whichisratherlikemagnetism.*“介词+which\whom\whose”引导的定语从句“介词+which\whom\whose”可引导限制性定语从句，也可引导非限制性定语从句，该结构中介词的选择取决于从句谓语动词的固定搭配，或先行词的习惯搭配。ThisisthecomputeronwhichhespentallhissavingsItiswrittenbyapersonwithwhomweareallfamiliar.*as引导的定语从句as引导的定语从句主要用于“such...as”及“thesame...as”的结构中，代替先行词是人或物的名词。as引导非限制性定语从句时，代替整个主句，从句可位于主句之前、之后或中间。Thesearenotsuchproblemsascanbeeasilysolved.(as代替先行词problems)Asismentionedabove,nosinglecompanyorgroupcancontrolwhathappensontheInternet.(as代替主语)2.主语从句1）主语从句可直接位于主语的位置，如果从句较长，谓语又较短，可用it作形式主语，而将从句放在句末。常见的句型有：*Itisafact\apity\aquestion\goodnewsthat...*Itseems\appears\happened\hasturnedoutthat...*Itisclear\important\likely\possiblethat...*Itissaid\reported\estimated\hasbeenprovedthat...Itissaidthatcomicbookscreateaconnectionbetweenpeopleofthesamegeneration.Itseemsthattheperformanceisveryuseful.2)what引导的主语从句表示“...的东西时”，一般不用it作形式主语。Whatwelackisexperience.3)what,who,when,why,whether等词含有各自的疑问意义，但它们引导的主语从句，都用陈述语序。Howtheplanistobecarriedoutshouldbediscussedagain.IdidknowwhyIfeltlikecrying.3.宾语从句1）宾语从句可位于及物动词、介词和某些形容词后。连词that常可省略。介词后一般接疑问词引导的宾语从句。inthat(因为),exceptthat(除了),butthat(只是）已构成固定搭配，其他介词后一般不接that引导的宾语从句。*IpromisedthatIwouldchangethesituation.*AllthisisdifferentfromwhatAmericanyoungpeoplewouldsayaboutfriendship.*Heiscertainthatwatchingsomuchtelevisionisnotgoodforchildren.*Thisarticleiswell-writtenexceptthatitisabittoolong.2）关于宾语从句连词的选择：①若从句来源于一个陈述句,那么,连词用that,在口语中that可以省略;②若从句来源于一个一般疑问句,连词则用if或whether;③若从句来源于一个特殊疑问句,则连词就是疑问词(如what,who,where,when等)*Theybelievethatthecomputerwillfinallytaketheplaceofhumanbeings.(他们相信计算机终将代替人类。)(从句本来就是陈述句)*IwonderwhetherIshouldsaysomethingforhimtotheheadmaster.(我不知道是不是该为他在校长跟前说点什么。)(从句来源于一般问句ShallIsaysomethingforhimtotheheadmaster?)*Heaskedmewherehecouldgetsuchmedicine.(他问我在哪儿能搞到那样的药。)(从句来源于特殊问句Wherecanhegetsuchmedicine?)3)宾语从句后如有宾补，要用形式宾语it来代替，而把宾语从句移至宾补之后。Hehasmadeitclearthathewouldnotchangehismind.4)在think,believe,suppose,expect等动词后的宾语从句中，如果谓语是否定的，一般将否定词移至主句谓语上，宾语从句则变成肯定形式。Hedidn'tthinkthatthemoneywaswellspent.4.表语从句在句子中作连系动词的表语的从句,它位于主句中的系动词之后。表语从句出现在结构为“主语+系动词+表语从句”的句子中。表语从句除可用that,what,when,why,whether,how等引导外，还可由because,asif(though)等引导。that常可省略。如主句主语为reason,只能用that引导表语从句，不可用because.*PerhapsthemostimportantthingtorememberisthatthereisnoonecommontypeoflifeinAmerica.*Thereasonwhysomanypeoplediedthereisthattherewerenotenoughfoodsupplies.*Itlooksasifsuccessfulinternationalculturalcommunicationwillmaketheworldsmaller.5.同位语从句同位语从句用于对前面出现的名词作进一步说明，一般用连词that引导，由于先行名词的意义不同，也可用whether,who,when,where,what,why,how等引导。常见的先行词有fact,idea,belief,news,hope,conclusion,evidence,suggestion,order,problem,report,decision.有时由于谓语较短，将同位语从句位于谓语之后。Shefinallymadethedecisionthatshewouldjointhefashionshow.IhadnoideahowmanybooksIcouldborrowatatime.Thenewscamethattheirteamhadwonthechampionship.6.状语从句*时间状语从句引导时间状语从句的从属连词和词组有：1）when,whenever,while,as,after,before,since,till,until,once等。Wehavelearntquitealotaboutitsincewecamehere.2)assoonas,hardly(scarcely)...when,nosooner...than,each(every)time,themoment,immediately(that)等。AssoonasIsentane-mailmessage,Ireceivedpositiveresponses.Themomentheheardthegoodnews,hejumpedwithjoy.*地点状语从句引导地点状语从句的连词是where,wherever.Wherevershewent,shetookherlittledaughterwithher.*原因、结果和目的状语从句1）引导原因状语从句的从属连词有：because,as,since,now(that),seeingthat,consideringthat,inthat等。Consideringthatheisafreshman,wemustsayheisdoingwell.2)引导结果状语从句的连词有：so...that,such...that,sothat,that,so等。MickeyMouseissoattractivethatthechildrenarereluctanttoleave.3)引导目的状语从句的连词有：sothat,inorderthat,forfearthat,lest等，从句常使用may,might,can,could,would等情态动词。Wegotupearlythismorningsothatwecouldcatchthefirstbustotherailwaystation.*条件和让步状语从句1）引导条件状语从句的连词和词组有