1.who指人,在从句中做主语

　　(1)TheboyswhoareplayingfootballarefromClassOne.

　　(2)YesterdayIhelpedanoldmanwholosthisway.

　　2.whom指人,在定语从句中充当宾语,常可省略.

　　(1)Mr.Liuistheperson(whom)youtalkedaboutonthebus.

　　(2)Mr.LingisjusttheboywhomIwanttosee.

　　注意：关系代词whom在口语和非正式语体中常用who代替,可省略.

　　(3)Themanwho/whomyoumetjustnowismyfriend.

　　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.

　　(2)Thisisthepen(which)heboughtyesterday.

　　4.that指人时,相当于who或者whom；指物时,相当于which.在宾语从句中做主语或者宾语,做宾语时可省略.

　　(5)Thenumberofthepeoplethat/whocometovisitthecityeachyearrisesonemillion.

　　(6)Whereisthemanthat/whomIsawthismorning?

　　5.whose通常指人,也可指物,在定语从句中做定语

　　(1)Hehasafriendwhosefatherisadoctor.

　　(2)Ioncelivedinahousewhoseroofhasfallenin.

　　whose指物时,常用以下结构来代替

　　(3)Theclassroomwhosedoorisbrokenwillsoonberepaired.

　　(4)Theclassroomthedoorofwhichisbrokenwillsoonberepaired.

　　(5)Doyoulikethebookwhosecoverisyellow?

　　(6)Doyoulikethebookthecolorofwhichisyellow?

　　三.介词+关系代词引导的定语从句

　　关系代词在定语从句中做介词宾语时,从句常由介词+关系代词引导

　　(1)Theschool(that/which)heoncestudiedinisveryfamous.

　　(2)Theschoolinwhichheoncestudiedisveryfamous.

　　(3)TomorrowIwillbringhereamagazine(that/which)youaskedfor.

　　(4)TomorrowIwillbringhereamagazineforwhichyouasked.

　　(5)We’llgotohearthefamoussinger(whom/that/who)wehaveoftentalkedabout.

　　(6)We’llgotohearthefamoussingeraboutwhomwehaveoftentalked.

　　注意：1.含有介词的动词短语一般不拆开使用,如：lookfor,lookafter,takecareof等

　　(1)Thisisthewatchwhich/thatIamlookingfor.(T)

　　(2)ThisisthewatchforwhichIamlooking.(F)

　　2.若介词放在关系代词前,关系代词指人时用whom,不可用who或者that；指物时用which,不能用that；关系代词是所有格时用whose

　　(1)Themanwithwhomyoutalkedismyfriend.(T)

　　(2)Themanwho/thatyoutalkedwithismyfriend.(F)

　　(3)TheplaneinwhichweflewtoCanadaisverycomfortable.(T)

　　(4)TheplaneinthatweflewintoCanadaisverycomfortable.(F)

　　3.“介词+关系代词”前可有some,any,none,both,all,neither,most,each,few等代词或者数词

　　(1)Helovedhisparentsdeeply,bothofwhomareverykindtohim.

　　(2)Inthebaskettherearequitemanyapples,someofwhichhavegonebad.

　　(3)Therearefortystudentsinourclassinall,mostofwhomarefrombigcities.

　　四．关系副词引导的定语从句

　　1.when指时间,在定语从句中做时间状语

　　(1)IstillrememberthedaywhenIfirstcametotheschool.

　　(2)Thetimewhenwegottogetherfinallycame.

　　2.where指地点,在定语从句中做地点状语

　　(1)ShanghaiisthecitywhereIwasborn.

　　(2)ThehousewhereIlivedtenyearsagohasbeenpulleddown.

　　3.why指原因,在定语从句中做原因状语

　　(1)Pleasetellmethereasonwhyyoumissedtheplane.

　　(2)Idon’tknowthereasonwhyhelooksunhappytoday.

　　注意：关系副词引导的从句可以由“介词+关系代词”引导的从句替换

　　(1)Thereasonwhy/forwhichherefusedtheinvitationisnotclear,

　　(2)Fromtheyearwhen/inwhichhewasgoingtoschoolhebegantoknowwhathewantedwhenhegrewup.

　　(3)Greatchangeshavetakenplace