精选优质文档-倾情为你奉上2012届高考一轮复习语法专项四:定语从句(一)定语从句一般由关系代词和关系副词引导1、关系代词:who, whom, whose, which, that, as2、关系副词:when, where, why关系代词和关系副词必须位于从句之首,主句先行词之后,起着连接先行词和从句的作用,同时在从句中又充当句子成分。e.g. She is the girl who sings best of all.(关系代词who在从句中作主语)The comrade with whom I came knows French.(whom在从句中作介词with的宾语)3、关系代词和关系副词的用法:1)当先行词为人时用who 作主语,whom作宾语;2)当先行词为物或整个句子时用which ,可作主语或宾语;3)先行词为人、物时用that ,可作主语或宾语;4)whose用作定语,可指人或物;5)关系副词when(指时间,在定语从句中作时间状语,where(指地点,在定语从句中作地点状语),why(指原因,在定语从句中作原因状语)。