1)Themanwholivesnexttousisapoliceman.2)YoumustdoeverythingthatIdo.上面两句中的man和everything是定语从句所修饰的词,叫先行词,定语从句放在先行词的后面。*引导定语从句的词有关系代词that,which,who(宾格whom,所有格whose)和关系副词where,when、why*关系词常有三个作用:1、引导定语从句2、代替先行词3、在定语从句中担当一个成分二、关系代词引导的定语从句*1.who指人,在从句中做主语TheboyswhoareplayingfootballarefromClassOne.*2.whom指人,在定语从句中充当宾语,常可省略。Theman(who/whom)youmetjustnowismyfriend.*3.which指物,在定语从句中做主语或者宾语,做宾语时可省略(1)Footballisagamewhichislikedbymostboys.(which在句子中做主语)(2)Thisisthepen(which)heboughtyesterday.(which在句子中做宾语)*4.that指人时,相当于who或者whom;指物时,相当于which,在定语从句中做主语或者宾语,做宾语时可省略。(1)Thepeoplethat/whocometovisitthecityareallhere.(在句子中做主语)(2)Whereistheman(that/whom)Isawthismorning?(在句子中做宾语)*5.whose通常指人,也可指物,在定语从句中做定语(1)Hehasafriendwhosefatherisadoctor.(2)Ilivedinahousewhoseroofhasfallenin.whose指物时,常用以下结构来代替(3)Theclassroomwhosedoorisbrokenwillsoonberepaired.=Theclassroomthedoorofwhichisbrokenwillsoonberepaired.1、只能使用that,不用which的情况:*1)当先行词是:all,any,anything,everything,nothing或被它们修饰时。Allthatcanbedonemustbedone.凡是能做的都必须做。*2)当先行词被形容词的最高级或序数词修饰时。例如:Thatisoneofthemostinterestingbooksthataresoldinthebookshop.那是这家书店出售的最有趣的书之一。Thefirstthingthatweshoulddoistogetsomefood.我们该做的第一件事是弄点吃的。*3)当先行词有:theonly,thevery,thesame,thelast等修饰时。例如:Mynecklaceisnottheonlythingthat'smissing.我的项链不仅是丢掉的东西。*4)当主句以who或which开头时,定语从句中引导词用that,不用which或who,以避免重复。例如:Whoisthegirlthatiswearingaredcoat?正穿一件红色外套的女孩子是谁?*5)当先行词既有人又有物时,用that。例如:Thewriterandhisnovelthatyouhavejusttalkedaboutarereallywellknown.你刚才谈起的那位作家以及他的小说确实很著名。2、只用which不用that的情况:*1)关系代词前有介词时;e.g.ThisistheroominwhichLuXunlived.*2)非限定性定语从句中;作宾语用的关系代词也不能省略。e.g.Thatnecklace,whichyougavemeasapresent,waslostyesterday.Hehasadaughter,whoworksinahospital.*3)先行词本身是that时;e.g.Theclockisthatwhichtellsthetime非限定性定语从句的作用是对所修饰的成分作进一步说明,通常是引导词和先行词之间用逗号隔开,将从句拿掉后其他部分仍可成立。CharlesSmith,whowasmyformerteacher,retiredlastyear.查理史密斯去年退休了,他曾经是我的老师。(非限)Thereissomebodyherewhowantstospeaktoyou这里有人要和你说话(限制性)*4)which还有一种特殊用法,它可以引导从句修饰前面的整个主句,代替主句所表示的整体概念或部分概念。在这种从句中,which可以作主语,也可以作宾语或表语,多数情况下意思是与andthis相似,并可以指人。Hedidverywellinthecompetition,whichmadehisparentsveryhappy.*关系代词whom,which在定语从句中作介词宾语时,可以和介词一起放于先行词与定语从句之间,有时为了关系紧凑也可以将whom与which与先行词紧挨着书写,而将介词置于定语从句的后面,Thatwastheroominwhichwehadlivedfortenyears.=Thatwastheroomwhichwehadlivedinfortenyears.*像listento,lookat,takecareof等固定短语动词,在定语从句中一般不宜将介词与动词分开。例如:Thisistheboywhomshehastakencareof.三、关系副词引导的定语从句*1、when:当主句中的先行词(即主句中被后面定语从句修饰的词)是表示时间意义的名词时,它只能作定语从句的时间状语,放在定语从句句首。如果定语从句的引导词是作该定语从句的主语或宾语,则要改用关系代词that或which来引导。例如:I'llneverforgetthedaywhenIwasborn.(=I'llneverforgetmybirthday.)我永远不会忘记我出生的日子。Theday(that)Ialwaysrememberinallmylifeismybirthday.我一生中最难忘的日子是我的生日。(that作定语从句thatIalwaysrememberinallmylife的宾语,that可以省略)*2、where:当主句中的先行词是表示地点意义的名词时,它只能作其所在的定语从句的地点状语,放在定语从句的句首。如果定语从句的引导词作该定语从句的主语或宾语时,也要改用关系代词that或which来引导。例如:ThefactorywherehisfatherworksisintheeastofthecityThatisthefactory(that)theyvisitedlastmonth.那就是他们上个月参观过的工厂。(引导词that作定语从句(that)theyvisitedlastmonth的宾语,that可以省略)如:Don’tforgetthetime(that)I’vetoldyou.不要忘记我告诉你的时间。(that用作told的宾语)I’llneverforgetthedayswhenIworkedwithyou.我永远不会忘记我与你共事的日子。(when用作状语)Heworksinafactorythat/whichmakesradioparts.他在一家制造无线电零件的工厂工作。(that/which在从句中用作主语,且不能省略)Heworksinthefactorywherehisfatherworked.他在他父亲工作过的那家工厂工作。(where作状语)*在定语从句的使用中,oneof后面的名词是复数,这个复数名词制约后面的定语从句的谓语动词,用复数;而在oneof前面有the或theonly时,后面引导的定语从句中的谓语动词则用单数形式。Heistheonlyoneofthestudentswhoiselected?Jasperisoneofthosepeoplewhoknowabouttheaccident.