.英语定语从句用法详解（初中） 在复合句中，修饰名词或代词的从句叫定语从句，被修饰的名词或代词叫先行词，引导定语从句的有关系代词who, whom, whose, which, that等和关系副词where, when, why等，关系代词和关系副词在定语从句中担任句子成份。1.由who引导的定语从句中，who用作主语，如：This is the boy who often helps me.2.由whom引导的定语从句中，whom用作宾语，如：The man whom you are waiting for has gone home.3.由whose引导的定语从句中，whose用作定语，如：Do you know the girl whose skirt is white?4.由which引导的定语从句中，which用作主语或谓语动词的宾语或介词的宾语，如：The room in which there is a machine is a work shop.The river which is in
