（一）定义及相关术语1.定语从句：修饰某一名词或代词的从句叫定语从句。定语从句一般紧跟在它所修饰的先行词之后。2.先行词：被定语从句修饰的词叫先行词。3.关系词：引导定语从句的词叫关系词。关系词有关系代词和关系副词关系代词有:that,which,who,whom,whose,as等关系副词有:when,where,why关系词通常有下列三个作用：A.引导定语从句；B.代替先行词；C.在定语从句中担当一个成分。Themanwhoisshakinghandswithmyfatherisapoliceman.（二）关系代词引导的定语从句1.who指人，在定语从句中作主语。TheboyswhoareplayingfootballarefromClassOne.Thosewhowanttogotothemuseummustbeattheschoolgateat7tomorrowmorning.YesterdayIhelpedanoldmanwhohadlosthisway.Thatistheteacherwhoteachesusphysics.2.whom指人，在定语从句中做宾语，常可省略。MrLiuistheperson(whom)youtalkedaboutonthebus.LiMingisjusttheboy(whom)Iwanttosee.Theprofessor(whom)youarewaitingforhascome.Thegirl(whom)theteacheroftenpraisesisourmonitor.注意：关系代词whom在口语或非正式文体中常可用who来代替，也可省略。Theman(whom/who)youmetjustnowismyoldfriend.3.which指物，在定语从句中做主语或宾语，做宾语时常可省略。Footballisagamewhichislikedbymostboys.Thefactorywhichmakescomputersisfarawayfromhere.Helikestoreadbookswhicharewrittenbyforeignwriters.Thehousewhichisbythelakelooksnice.Thisisthepen(which)heboughtyesterday.Thefilm(which)theywenttoseelastnightwasnotinterestingatall.4．that指人时，相当于who或whom；指物时，相当于which。在定语从句中作主语或宾语，作宾语时常可省略。Thenumberofpeoplethat/whocometovisitthiscityeachyearreachesonemillion.Whereisthemanthat/whomIsawthismorning?Thepersonthat/whomyouintroducedtomeisverykind.Theseasonthat/whichcomesafterspringissummer.YesterdayIreceivedaletterthat/whichcamefromAustralia.5.whose通常指人，也可指物，在定语从句中做定语。Ivisitedascientistwhosenameisknownalloverthecountry.Hehasafriendwhosefatherisadoctor.Ioncelivedinthehousewhoseroofhasfallenin.注意：指物时，常用下列结构来代替：Theclassroomwhosedoorisbrokenwillsoonberepaired.Theclassroomthedoorofwhichisbrokenwillsoonberepaired.Doyoulikethebookwhosecoverisyellow?Doyoulikethebookthecoverofwhichisyellow?（三）“介词+关系代词”引导的定语从句关系代词在定语从句中作介词宾语时，从句常常由“介词+关系代词”引出。Theschool(which/that)heoncestudiedinisveryfamous.Theschoolinwhichheoncestudiedisveryfamous.TomorrowI’llbringherethemagazine(which/that)youaskedfor.TomorrowI’llbringherethemagazineforwhichyouasked.Thisistheboy(whom/who/that)Iplayedtenniswithyesterday.ThisistheboywithwhomIplayedtennisyesterday.We’llgotohearthefamoussinger(whom/who/that)wehaveoftentalkedabout.We’llgotohearthefamoussingeraboutwhomwehaveoftentalked.ThemanagerwhosecompanyIworkinpaysmuchattentiontoimprovingourworkingconditions.ThemanagerinwhosecompanyIworkpaysmuchattentiontoimprovingourworkingconditions.注意：1.含有介词的短语动词一般不拆开，介词仍放在短语动词的后面。如：lookfor,lookafter,takecareof等。Thisisthewatch(which/that)Iamlookingfor.ThisisthewatchforwhichIamlooking.Thebabiesafterwhomthenurseislookingareveryhealthy.Thebabies(whom/who/that)thenurseislookingafterareveryhealthy.２.若介词放在关系代词前，关系代词指人时只可用whom，不可用who,that；关系代词指物时只可用which，不可用that。关系代词是所有格时用whose。Themanwithwhomyoutalkedjustnowismyneighbour.Themanwiththat/whoyoutalkedjustnowismyneighbour.TheplaneinwhichweflewtoCanadawasreallycomfortable.TheplaneinthatweflewtoCanadawasreallycomfortable.×√×３.“介词+关...
