5、从句中担任什么成分。先行词:指被定语从句修饰的名词、代词。一般先行词出现在定语从句的前面。关系词的作用:关系词常有3个作用：①连接作用，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。 关系词通常有下列三个作用：A、引导定语从句；B、代替先行词；C、在定语从句中担当一个成分。例如： The man who is shaking hands with my father is a policeman. 该句中，who is shaking hands with my father 是定语从句，修饰先行词th
6、e man， “who”是引导定语从句的关系词，代替先行词the man，在定语从句中作主语。（二）关系代词引导的定语从句1．who 指人，在定语从句中作主语或者宾语。The boys who are playing football are from Class One. 正在踢足球的男孩是一班的。Those who want to go to the museum must be at the school gate at 7 tomorrow morning. 想去博物馆的人必须在明晨7点到大门口集合。Ye
7、sterday I helped an old man who had lost his way. 昨天我帮助了一位迷路的老人。That is the teacher who teaches us physics. 那就是教我们物理的老师。2．whom 指人，在定语从句中做宾语，常可省略。 Mr Liu is the person ( whom ) you talked about on the bus. 刘先生就是你们在公共汽车上谈论的那个人。Li Ming is just the bo
8、y ( whom ) I want to see. 李明正是我想要见的男孩。The professor ( whom ) you are waiting for has come. 你正在等的教授已经来了。The girl ( whom ) the teacher of
