在初中英语中要求学生掌握关系代词that,which,who 引导的定语从句. 

        一．关系代词引导的定语从句

       1. 关系代词用来指代先行词是人或物的名词或代词

句子成分　 用于限制从句或非限制性从句　　 只用于限制性从句

　　　   代替人　　　　代替物　　　　　　代替人或物

主语　     Who　　　　　which　　　　　　   that

宾语　     Whom　　　　 which　　　　　　   that

      例1：This is the detective who came from London.
      例2：The book which I am reading is written by Tomas Hardy.
      例3:   The man who(m) you are talking to is my good friend.　　
      例4：This is the room that Shakespeare was born in.

２．关系代词的用法
　　(1) 如果先行词是all, much, anything, something, nothing, everything, little, none等不定代词，关系代词一般只用that，不用which。例如：
All the people that are present burst into tears.

　　(2) 如果先行词被形容词最高级以及first, last, any, only, few, mush, no, some, very等词修饰，关系代词常用that,不用which, who，或whom。例如：

       This is my first time that I have seen her.

       但是在17单元65课练习册中第三题第七个练习“All the women ____ were working in that factory had a day off on Women's Day. ”参考书给出的答案就是who 。同样，在17单元66课中出现了这么一句话 I'll shoot anyone who moves.这说明语法并不是宪法，有时很灵活，不必拘泥于某些语法书的说法。
　　(3) 非限制性定语从句中，不能用关系代词that,作宾语用的关系代词也不能省略。例如：
       The boy,who is good at soccer,comes from Xinjiang.

       That necklace,which you gave me as a present,was lost yesterday.
　　(4) which还有一种特殊用法，它可以引导从句修饰前面的整个主句，代替主句所表示的整体概念或部分概念。在这种从句中，which可以作主语，也可以作宾语或表语，多数情况下意思是与and this 相似，并可以指人。例如：

　　He did very well in the competition, which made his parents very happy.
　　(5) that可指人或物，在从句中作表语，（指人作主语时多用who）仅用于限制性定语从句中。
　　(6) 如果作先作词的集体名词着眼于集体的整体，关系代词用which;若是指集体中的各个成员，则用who。
　　(7) 先行词有两个，一个指人，一个指物，关系代词应该用that。例如：
　　The boy and the dog that are in the picture are very lovely.
　　(8) 如果先行词是anyone, anybody, everyone, everybody, someone, somebody,关系代词应该用 who 或whom.　　

       Is there anyone here who will go with you?

３．"介词＋关系代词"是一个普遍使用的结构

　　(1) "介词＋关系代词"可以引导限制性定语从句，也可以引导非限制性定语从句。"介词＋关系代词"结构中的介词可以是 in, on, about, from, for, with, to at, of, without 等，关系代词只可用whom或 which,不可用 that 。
例:Is that the house in which you live ?
　　(2)像listen to, look at, take care of等固定短语动词，在定语从句中一般不宜将介词与动词分开。例如：
　　 This is the boy whom she has taken care of.