关系词指代人或物定语从句中充当的成分关系代词that人或物主语、宾语、表语which物或主句内容主语、宾语、表语或定语who人主语、宾语、表语whom人宾语whose人或物定语as人或物或主句内容主语或宾语关系副词when时间状语where地点状语why原因状语whose是一个表示所属关系的词,在定语从句中作定语,相当于my,his,her,its,their等,修饰人或物。ofwhich可以代替whose指物,词序一般是:the+名词+ofwhich或ofwhich+the+名词。ofwhom可以代替whose指人,词序是:the+名词+ofwhom或ofwhom+the+名词。Thisisthescientistwhosenameisknownalloverthecountry.=Thisisthescientistthenameofwhomisknownalloverthecountry.这就是那位全国知名的科学家。Theclassroom,whosedoorisbroken,willsoonberepaired.=Theclassroom,thedoorofwhichisbroken,willsoonberepaired.1.与定语从句中的动词构成搭配。Theman(who/whom/that)ItalkedaboutatthemeetingisfromBeijingUniversity.=ThemanaboutwhomItalkedatthemeetingisfromBeijingUniversity.在会议中我与之谈话的那个人是从北京大学来的。Inthedarkstreet,therewasn'tasinglepersontowhomshecouldturnforhelp.在漆黑的大街上没有一个人能为她提供帮助。[注意]有些固定短语中的介词不能拆开移到关系代词前如:takecareof,lookfor,lookafter,careforThisistheperson(who/whom/that)youarelookingfor.这就是你找的那个人。2.与定语从句所修饰的先行词构成搭配。Hebuiltatelescope,throughwhichhecouldstudytheskies.他架起一架望远镜,通过它他可以研究天空。Hecametoafarm,onwhichhefinallysettled.他来到一个农场,最终在那里定居下来了。as与which都可以代指主句中的一部分或整个句子的内容,有时可以互换。Hemarriedher,as(which)wasnatural.很自然地,他和她结婚了。但在下列情况下一般只能用as。(1)as引导定语从句可以放在句首,而which则不能。Asweknow,morethanseventypercentoftheearthiscoveredwithwater.正如我们所知,地球表面的70%以上由水覆盖。(2)as可表示“正如,正像”,而which无此意。此时,as从句中常有know,expect,happen,pointout,plan,suggest等单词或短语。(3)当先行词被thesame,such修饰时,定语从句需用as引导。Iboughtthesamebookasyouhave.我买了一本跟你的一样的书。Thisissuchaneasyquestionaseveryonecanworkout.=Thisissuchaneasyquestionthateveryonecanworkitout.这是这么一个简单的问题,每个人都能解决。He'llmarryasprettyagirlashecanfind.他将与他能发现的最漂亮的女孩结婚。[注意]当先行词被thesame修饰时,that也可引导定语从句,但意义有所不同。thesame...as(指同样或同类的),thesame...that(指同一个)ThisisthesamewatchasIlost.这块表与我丢的那块一样。ThisisthesamewatchthatIlost.这就是我丢的那块表。1.“介词+where”引导的定语从句。有时我们可以见到“介词+where”引导的定语从句,此时要和“介词+which”引导的定语从句从意思上加以区别。Hisheadsoonappearedoutofthewindow,fromwherehesawnothingbuttrees.他的头很快从窗口探了出来,从那里除了树木他什么也看不到。(fromwhere相当于fromoutofthewindow,而不是fromthewindow)Chinaisthebirthplaceofkites,fromwherekiteflyingspreadtoJapan,Korea,ThailandandIndia.中国是风筝的故乡,从这里放风筝传到了日本、朝鲜、泰国和印度。2.分隔式定语从句。定语从句有时不直接紧靠着先行词,中间由一个定语、状语或谓语隔开。ThereisanexpressioninhiseyesthatIcan'tunderstand.我不能理解他眼中表达的东西。ThedaysaregoneforeverwhentheChinesepeoplewerelookeddownupon.中国人民被轻视的日子一去不复返了。3.抽象地点类先行词后的定语从句。当先行词为stage,situation,point,case等词且关系词在从句中作状语,这时用where引导定语从句。Theyhavereachedthepointwheretheyhavetoseparatewitheachother.他们已经到了必须分手的地步。IcanthinkofmanycaseswherestudentsobviouslyknowalotofEnglishwordsandexpressionsbutcan'twriteagoodessay.我能想出许多这样的场合,很显然学生知道许多英语词汇但是却写不出一篇好文章。定语从句中的主谓一致问题(1)关系代词在定语从句中作主语时,从句谓语动词的人称和数要和先行词保持一致(2)oneof+复数名词+关系代词+复数动词;而theonlyoneof+复数名词+关系代词+单数动词(3)非限制性定语从句中,由关系代词as或which代替整个主句时,从句谓语动词要用第三人称单数指物时,定语从句中的关系代词只能用that的情况:(1)当先行词为everything,anything,nothing,theone,none,all,much,few,any,little等不定代词时(2)当先行词被theonly,thevery,all,much,few,any,little,no修饰时(3)当先行词是序数词、形容词最高级或者先行词被序数词、形容词最高级修饰时(4)先行词既有人又有物时(5)当主句的主语是疑问词who或which时,为避免重复要用thatWhoisthemanthatisstandingbythedoor?Whichofthetwocowsthatyoukeepproducesmoremilk?(6)有两个定语从句时,其中一个关系代词已用which,另一个则用that,如:Theyhavesetupacompany,whichdealswiththethingsthatarerelatedtoenvironmentprotection.(7)当先行词在主句中作表语,而关系代词也在从句中作表语时,只用that,如:Hangzhouisnomorethecitythatitusedtobe.指人时,定语从句中的关系代词只能用who的情况:(1)当先行词是anyone,those时,如Isthereanyonewhoisreadytohelptheinjuredperson?(2)有两个定语从句时,其中一个关系代词已用that,另一个宜用who。