定語從句本質(zhì)就是一個句子作定語，緊緊跟在所修飾名詞（先行詞）的后面。那從句如何和主句連接在一起呢？英語人想到了一個辦法，那就是對定語從句打頭的單詞進行一些特殊規(guī)定，只能用以下的單詞引領(lǐng)定語從句：who(以及who的親戚whoever,whom,whomever,whose,whosever),which(以及它的朋友whichever),thatwhen(以及它的朋友whenever)where(以及它的朋友whichever)why這幾個詞有一個響亮的名字“關(guān)系詞”為什么叫關(guān)系詞呢？那是因為這幾個詞使得從句和主句產(chǎn)生了關(guān)系，融合成了一個主從復合句。關(guān)系詞有兩個作用。一是在從句中充當成分，使從句語法結(jié)構(gòu)完整（從句雖然是一個從句，但是也是一個句子，主謂賓啥的都不能缺了）。一是指代先行詞，使從句的意義完整。這6個（以上14個詞簡化為that,which,who,when,where,why,其他的也不常用，會造成記憶負擔）關(guān)系詞，根據(jù)在從句中充當?shù)某煞?，又分為關(guān)系代詞(主語、賓語、表語)和關(guān)系副詞（狀語）。（一）關(guān)系代詞引導的定語從句1、指代人的關(guān)系代詞：who，在從句中多做主語或賓語，做賓語可用whom,也可以省略Thegirl(whom/who)youjustmetisCathy.此處who在從句中作met的賓語，who/whom/省略都可以IamgoingtoseeafriendwhohasjustcomebackfromtheUS.此處who在從句中做hascomeback的主語，只能填whoIwillgivethisgifttothestudentwhoevercomesnext.我會把這個禮物給下一個進來的同學whoever:不管是誰2、指代物的關(guān)系代詞：which，在從句中多做主語或賓語，作賓語時可省略。AnotherbigearthquakewhichwasalmostasstrongasthefirstoneshookTangshan.此處which作為從句的主語，替代先行詞earthquakePhilosophyisasubject(which)Iknowlittleabout.此處which在從句中作know的賓語，替代先行詞subject,可省略3、既可以指代人又可指物的關(guān)系代詞：that,在從句中多做主語或賓語，作賓語時可省略。Thenextdaypeopleputupsheltersintheopenairmadewithanything(that)theycouldfind.此處that指代先行詞anything,在從句中作find的賓語，可省略Isshethegirlthatsellsnewspapers?此處that指代先行詞girl,在從句中作sell的主語。4、whose既可以指代人又可物，在從句中作定語。Anumberofchildrenwhoseparentshaddiedinthequakeweresenttolivewithfamiliesinothercities.whose指代children's孩子的，修飾parentsTheclubwhosemembersaremusicfansmeetintheschoolgardeneverySaturdayafternoon.whose指代club's,修飾members5、“介詞+關(guān)系代詞”引導的定語從句介詞+which引導的定語從句修飾指物的名詞；介詞+whom引導的定語從句修飾指人的名詞Thepartsoftowninwhichtheyhadtoliveweredecidedbywhitepeople.介詞in也可以放在最后Thepartsoftownwhichtheyhadtoliveinweredecidedbywhitepeople.Themoneywithwhichyouweretobuydogfoodisgone.介詞with也可以放在后邊Themoneywhichyouweretobuydogfoodwithisgone.MandelawastheblacklawyertowhomIwentforadvice.介詞to可以放在后邊Mandelawastheblacklawyerwho/whomIwenttoforadvice.注意：若to在前，后邊必須用賓格whom;若to在后邊，who和whom都可Sheisthepersonfromwhomyoucanexpectgoodadvice.介詞from可以放在后邊Sheisthepersonwho/whomyoucanexpectgoodadvicefrom.（二）關(guān)系副詞引導的定語從句1、關(guān)系副詞when在其引導的定語從句中作時間狀語，修飾的是表示時間的名詞。Tip:whendidyoumeetTom?怎么回答？一般是“ImetTominthemorning/onSunday/at9”,所以我們可以理解when=介詞(in/on/at)+時間名詞ThetimewhenIfirstmetNelsonMandelawasaverydifficultperiodofmylife.when相當于介詞+先行詞time,從句可改寫為：IfirstmetNelsonMandelaatthattime.是一個結(jié)構(gòu)和意義都完整的句子。Weddingisanoccasionwhenbrideisthemostbeautiful.婚禮是新娘打扮得最漂亮的時候。when=ontheoccasion,從句可改寫為：brideisthemostbeautifulontheoccasion.Thedaysaregonewhenphysicalstrengthwasallyouneededtomakealiving.定語從句和先行詞可能沒有那么緊密的挨著2、關(guān)系副詞where在其引導的定語從句中作地點狀語，修飾的是表示地點的名詞。(1)修飾表示具體地點概念的名詞：Thepartsoftownwheretheyhadtoliveweredecidedbywhitepeople.同理，where=介詞+先行詞=inthetown,從句可改寫為：theyhadtoliveinthetown.TheplacesoutsidethetownswheretheyweresenttolivewerethepoorestpartsofSouthAfrica.where=in+先行詞towns，從句可改寫為：theyweresenttoliveinthetowns.(2)修飾表示抽象地點概念的名詞:Wehavereachedastagewherewehavealmostnorightsatall.IhavereachedapointinmylifewhereIamsupposedtomakedecisionsofmyown.Hegothimselfintoadangeroussituationwhereheislikelytolosecontrolovertheplane.Teachingisajobwhereyouaredoingsomethingseriousbutinteresting.Lifeisalongracewherewecompetewithotherstogobeyondourselves.Latercaseswillbeintroducedtoreaderswhereconsumercomplaintshaveresultsinchangesinthelaw.Weareinapositionwherewemaylosealargesumofmoney.Thiscompanyhasnowintroducedapolicywherepayrisesarerelatedtoperformanceatwork.3、關(guān)系副詞why在其引導的定語從句中作原因狀語，先行詞一般是reasonCanyoutellmethereasonwhy/forwhichyouwanttoleaveyourpresentemployer?先行詞是reason,關(guān)系詞可以是why,和forwhich,why=forwhich=for+先行詞=forthereasonIdidn’tgetapayrise,butthatwasn’tthereasonwhy/forwhichIleft.注意區(qū)別：Thereasonwhyheislateisknowntoall.此處關(guān)系詞是why=forwhich=forthereason,在從句中作原因狀語，從句可改寫為heislateforthereason,結(jié)構(gòu)完整，語意清楚。Thereasonthathegavemeisnotconvincing.此處關(guān)系詞是that,指代先行詞reason,在從句中作gave的賓語，從句可改寫為hegavemethereason,結(jié)構(gòu)完整，語意清楚。（三）關(guān)系代詞和關(guān)系副詞的區(qū)別代詞可以做主語、表語、賓語、補語副詞可以做狀語關(guān)系代詞和關(guān)系副詞在從句中也如此思考：先行詞是表示時間的名詞，定語從句一定由when來引導嗎？先行詞是表示地點的名詞，定語從句一定由where來引導嗎？試比較以下兩組句子：①Ireturnedtothecity__________Ivisitedlastyear.解析：如果先行詞是that/which,那么它指代city在從句中充當成分，如果先行詞是where,那么介詞+city在從句中充當成分，我們就看看那個會使從句成為完整的句子？如果用that/which，從句是Ivisitedthecitylastyear.結(jié)構(gòu)完成，語意清楚如果用where,從句是Ivisitedinthecitylastyear.結(jié)構(gòu)不對所以答案是thatIreturnedtothecity__________Igrewup.如果用that/which,從句是Igrewupthecity.結(jié)構(gòu)不完整。如果用where,從句是Igrewupinthecity.結(jié)構(gòu)完整，語意清楚。所以答案是where②I’llneverforgetthedays__________wespenttogether.如果用that/which,從句是wespentthedaystogether.結(jié)構(gòu)完整。如果用when，從句是wespendinthedaystogether,語法不對呀~~所以答案是that/whichI’llneverforgetthedays__________weworkedtogether.如果用that/which,從句是weworkedtogetherthedays.這是啥？如果用when，從句是weworkedtogetherinthosedays.語法正確，語意完整。所以答案是when（四）特殊的先