Readthesentencesandfindoutthedifferencesbetweenthem.1)Theoldmanthatyoumetattheschoolgateisaprofessor.Theoldmanisaprofessor,whoisover80yearsold.2)ThetemplewhichwevisitedlastweekdatesfromSongDynasty.Thetemple,whichisaplaceofinterestinourhometown,datesfromSongdynasty.1)定语从句有限制性和非限制性两种。限制性定语从句是先行词不可缺少的部分，去掉它主句意思往往不明确；非限制性定语从句是先行词的附加说明，去掉了也不会影响主句的意思，它与主句之间通常用逗号分开，例如：•Thisisthehousewhichweboughtlastmonth.（限制性）•Thehouse,whichweboughtlastmonth,isverynice.（非限制性）2)当先行词是专有名词或物主代词和指示代词所修饰时，其后的定语从句通常是非限制性的，例如：CharlesSmith,whowasmyformerteacher,retiredlastyear.Myhouse,whichIboughtlastyear,hasgotalovelygarden.Thisnovel,whichIhavereadthreetimes,isverytouching.3)非限制性定语从句还能将整个主句作为先行词，对其进行修饰，这时从句谓语动词要用第三人称单数，例如：HeseemsnottohavegraspedwhatImeant,whichgreatlyupsetsme.Liquidwaterchangestovapor,whichiscalledevaporation.说明：关系代词that和关系副词why不能引导非限制性定语从句1.SunYat-sen,whobecamePresidentoftheRepublicofChinain1912,diedin1925.2.ThebuildingoftheGrandCanal,whichistheworld’slongestcanal,beganin486BC.3.Thesectionofthecanal,whichwasbuiltintheseventhcentury,wasmainlyusedforricetransportation.Doactivity2andcheckyouranswers.1.TheYangtzeriver,whichismorethan6,000kilometerslong,isthethirdlongestriverintheworld.2.TheThreeGorgesDam,whichwillgeneratealargeamountofenergy,isthebiggestconstructionprojectinChina.3.MaoZedong,whoisagreatleaderofChina,wroteapoemaboutadamacrosstheYangtzeRiver.Doactivity3andcheckyouranswers.限定性定语从句和非限定性定语从句的区别1.限制性定语从句修饰前面的名词，使其有别于其他同类名词，可以清楚表达所修饰名词的特征。Themanwhotoldmethisrefusedtogivemehisname.Thenoisethathemadewokeeverybodyup.2.非限制性定语从句位于名词之后，不做限定性描述，仅作说明和补充。Peter,whohadbeendrivingallday,suggestedstoppingatthenexttown.Shegavemethisdictionary,whichshehadboughtinthebookshop.比较以下句子:Thecollegestudentswhoknewthetruthleftthesmalltown.Thecollegestudents,whoknewthetruth,leftthesmalltown.Hehasasonwhoworksinahospital.Hehasason,whoworksinahospital.3.在限制性定语从句中，如果关系代词在从句中作宾语，常可省略。非限制性定语从句中，关系代词不能省略。关系代词跟在介词之后不能省略。Theletter(which/that)IreceivedwasfromBen.Theytalkedofthingsandpersons(that)theyrememberedintheschool.CarolsaidtheworkwouldbedonebyOctober,whichpersonallyIdoubtverymuch.Contractionofattributiveclauses有些定语从句可以缩略为各种短语，如分词短语、形容词短语、名词短语、介词短语及动词不定式短语等，且句意不受影响。我们称这一语法现象为定语从句的缩略。•有些定语从句可直接略去作主语的关系代词（who,which,that）和部分谓语（am,is,are,were等，从而使之缩略为现在分词短语或过去分词短语作后置定语。例如：1)Iknowthemen(whoare)sittinginthatcar.2)Theboyshelpedthepeople(thatwere)hurtintheaccident.3)Theproblem(whichis)botheringeverybodyisthelackofmoney.4)Thebook(thathasbeen)giventohimisanEnglishnovel.•有些定语从句不能按上述方法直接缩略，而需变动词为分词。这类定语从句一般缩略为现在分词短语，且在缩略时要考虑现在分词的时态和词态特征。例如：5)Themanwhoownsthatcarwillbefinedforillegalparking→Themanowningthatcarwillbefinedforillegalparking.6)Bill,whohadtakenchemistryinhighschool,offeredtohelphim.→Bill,havingtakenchemistryinhighschool,offer...
