Non-restrictiveAttributiveClauses非限制性定语从句定语从句是由关系代词和关系副词引导的从句，其作用是作定语修饰主句的某个成分，定语从句分为限定性和非限定性从句两种。Thisisthehousewhichweboughtlastmonth.2.Thehouse,whichweboughtlastmonth,isverynice.3.CharlesSmith,whowasmyformerteacher,retiredlastyear.4.Thisnovel,whichIhavereadthreetimes,isverytouching.限制性定语从句:对所修饰的词加以限定,表示“…的人或东西”。定语从句去掉以后，句子的意思常常不完整。David,whoisoneofmybestfriends,comesfromNewYork.大卫从纽约回来了，他是我最好的朋友。DavidcomesfromNewYork.大卫从纽约回来了。a)HissonwhoisadoctorisnowvisitingtheUSA.b)Hisson,whoisadoctor,isnowvisitingtheUSA.2.a)ThisistheplacewhereIlivedtenyearsago.b)SheisgoingtospendthewinterholidayinMacao,whichreturnedtoChinain1999.3.a)HeisamanwhoIcanaskforhelp.b)Hisfather,whoworksinBeijing,camebackyesterday.限制性定语从句和先行词关系密切，如果去掉从句，剩余部分意义不完整；非限制性定语从句只是先行词的附加说明，如果去掉从句，意义仍然完整。在非限制性定语从句中，不能用that引导定语从句，只能用who/whom指人，用which指物，而且引导词不能省略。例如：Thechairman,whospokefirst,satonmyright.Hisspeech,whichboredeveryone,wentonandon.I’mseeingthemanagertomorrow,whenhewillbebackfromShanghai.限制性&非限制性定语从句比较非限制性定语从句还能修饰整个主句,这时从句谓语动词要用第三人称单数。例如：HeseemsnottohavegraspedwhatImeant,whichgreatlyupsetsme.他似乎没理解我的意思，这使我心烦。Liquidwaterchangestovapor,whichiscalledevaporation.液态水变为蒸汽，这就叫做蒸发。1.TheygotmarriedinSeptember.Iwastheninthecountryside.3.WouldyouliketomeetDavidJohnson?Hislatestnovelhasbecomeabest-seller.4.IliketheSummerPalaceverymuch.Itusedtobearoyalgarden.5.Frankisinchargeoftheschool.Heismycousin.5.Thestoryhappenedin1997.Iwasstillalittlebabythen.7.Ihaveaphoneanditisbroken.Itisinthekitchen.8.Thefactorywascloseddown.Itsownerhadbeenputintoprison.Fillintheblankswithproperrelativewords.1.Thefamousbasketballstar,_____isanAmerican,cametoChinayesterday.2.Inthosedays,sheusedtogotoMr.black,with_____shehadawonderfultime.3.Iboughtacaryesterday,_____costmealot.4.Xi’an,______Ivisitedlastyear,isaniceoldcity.5.HewillcometoseemenextJuly,____hewon’tbesobusy.6.Theschool,_______Ioncestudied,wasbuiltthirtyyearsago.7.Johnsaidhe’dbeenworkingintheofficeforanhour,_______wastrue.1.(2014北京)Iborrowedthebo