Unit4语法辅导（一）限定性定语从句1.that即可代表事物也可代表人，which代表事物；它们在从句中作主语或宾语，that在从句中作宾语时常可省略关系词，which在从句中作宾语则不能省略。而且，如果which在从句中作“不及物动词＋介词”的介词的宾语，注意介词不要丢掉，而且介词总是放在关系代词which的前边，但有的则放在它原来的位置。2.which作宾语时，根据先行词与定语从句之间的语义关系，先行词与which之间的介词不能丢。3.代表物时多用which，但在带有下列词的句子中用that而不用which，这些词包括all,anything,much等，这时的that常被省略。4.who和whom引导的从句用来修饰人，分别作从句中的主语和宾语，whom作宾语时，要注意它可以作动词的宾语也可以作介词的宾语。5.where是关系副词，用来表示地点的定语从句。6.when引导定语从句表示时间［注］值得一提的是，表示时间“time"一词的定语从句只用when引导，有时不用任何关系代词，当然也不用that引导。BythetimeyouarriveinLondon,wewillhavestayedtherefortwoweeks.IstillrememberthefirsttimeImether.Eachtimehegoestobusinesstrip,hebringsalotoflivingnecessities,suchastowers,soap,toothbrushetc.7.whose是关系代词，修饰名词作定语，相当于所修饰成分的前置所有格。8.当从句的逻辑主语是some,any,no,somebody,anybody,nobody,something,anything,everything或nothing时，常用thereis来引导。（二）定语从句及相关术语1.定语从句：修饰一个名词或代词的从句称为定语从句，一般紧跟在它所修饰的先行词后面。2.关系词：引导定语从句的关联词成为关系词关系词有关系代词和关系副词。关系代词有that,which,who,whom,whose,as等；关系副词有where,when,why等。关系词常有3个作用：1，引导定语从句。2，代替先行词。3，在定语从句中担当一个成分。（三）关系代词引导的定语从句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.如果在从句中做宾语,就用whom或who.比如:Heisthemanwhom/whoItalkto.如果是在从句中作主语就只能用who.比如:HeisthemanwhohasanEnglishbook.4.that指人时，相当于who或者whom；指物时，相当于which。在定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?（四）注意介词+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，...
