（一）定义及相关术语1. 定语从句：修饰某一名词或代词的从句叫定语从句。定语从句一般紧跟在它所修饰的先行词之后。 2. 先行词：被定语从句修饰的词叫先行词。3. 关系词： 引导定语从句的词叫关系词。 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 : when, where, why 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。 The man who is shaking hands with my father is a policeman. （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。The boys who are playing football are from Class One.Those who want to go to the museum must be at the school gate at 7 tomorrow morning. Yesterday I helped an old man who had lost his way.That is the teacher who teaches us physics. 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 thebus. Li Ming is just the boy ( whom ) I want to see. The professor ( whom ) you are waiting for has come.The girl ( whom ) the teacher often praises is our monitor. 注意：关系代词 whom 在口语或非正式文体中常可用 who 来代替，也可省略。The man ( whom / who ) you met just now is my oldfriend. 3. which 指物，在定语从句中做主语或宾语，做宾语时常可省略。 Football is a game which is liked by most boys.The factory which makes computers is far away from here. He likes to read books which are written by foreign writers.The house which is by the lake looks nice. This is the pen ( which ) he bought yesterday.The film ( which ) they went to see last night was not interesting at all. 4 ． that 指人时，相当于 who 或 whom ；指物时，相当于 which 。在定语从句中作主语或宾语，作宾语时常可省略。The number of people that / who come to visit this city eachyear reaches one million. Where is the man that / whom I saw this morni...
