which和as的用法归纳及比较.doc

which和as的用法归纳及比较.docwhich和as的用法归纳及比较一、which引导名词从句的用法比较which作为连接代词,可以引导名词从句,在从句中作主语、宾语、定语或表语等语法成分。that在引导名词从句时,只起连接主句和从句的作用,其本身没有任何含义,不翻译o例如•■(1)Whichisbetterdependsonthesetwoclothes'quality.(2)ThatTonycan'tswim■ISunbelievable.(3)'tknowwhich1shouldchoose,becausetheredandtheyellowareboth(4 ) ,which和that都可以引导主语从句和宾语从句,但是在(1)句和(3)句中which在从句中分别作了主语和宾语成分,而在(2)句和(4)句中that在从句中不作任何成分,只起到连接主句和从句的作用。二、which引which作为关系代词,可以引导定语从句,例导定语从句的用法比较在从句中可以代替物作主语和宾语等语法成分。如 :(5)Thisisthebook which/thatIboughtlastweek.(6)Theclothes,whichareoverthere,(5)句和(6)句中我们可以看到which可以引导限制性和非限制性定语从句,并分别在句屮作宾语和主语成分。一般情况下,that和which在引导定语从句屮代替物时可以互用,但以下情况一般要用which:非限制性定语从句中关系代词一般要用which;关系代词前如有介词、关系代词须用which,如把介词移至动词后,可用that(或省略);如果先行词是that,关系代词应用which:如先行词和定语从句之间被其它较长的成分分隔,常用which;在"those+复数形式的名词〃结构中,其后的关系代词多用which;一个句子中如有两个定语从句,第一个定语从句用了关系代词that,第二个从句中的关系代词宜用whicho但在平行结构中,应重复同一个关系代词。例如:<7)Shewasawardedagoldmedal,whichthewholefamilyconsideredagreathonor.(which引导非限制定语从句)(8)There'sonlyoneissueaboutwhichtheydisagree.(which前有介词about)(9)Thisisthepen(that)shewaslookingfor.(介词移至动词后)(10)Ihavethatwhichyougaveme.(先行词是that)(11)LarrytoldherthestoryoftheyoungairmanwhichInarratedatthebeginningofthisbook.(先行词和关系彳弋词相隔)<12)Ashopshouldkeepastockofthosegoodswhichsellbest.(those+复数形式的名词)Thisisthebookthatyouboughtwhichyouhavelost.(两个定语从句中)Ihaveahousewhichislocatedonthehills,whichfac