定语从句
1、定语从句的句法特点及关系代词、副词：
关系代词：who, whom, whose, that, which, as
关系副词：when, where, why
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. 所有在场的人都哭了。
(2) 如果先等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：
He is the last person that could have done such a thing. 他绝不是做这种事的人。
(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：
There are about seven million people taking part in the election, most of whom are well educated. 有700万人参加了这次竞选，其中大部分都受过良好教育。
(4) 非限制性定语从句中只能用which，可以指代前面的一个词，也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 succeeded in the competition, which made his parents very happy.
他比赛获胜，令他父母十分欣慰。
(5) 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。
(6) 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.
(7) 如果先行词是anyone, anybody, everyone, everybody, someone, somebody, 关系代词应该用 who 或whom，不用 which。例如：
Is there anyone here who will go with you?