英语定语从句介词+关系词的用法

定语从句里面的关系代词的用法.
1.常用的关系代词：which, that, who, whom.Whom现在用的很少.前面有介词只能用which,不能用that.
2. 关系代词在考试中的特殊情况.
What:
1)它是子母同体.相当于一个关系代词以及一个先行词.What前面不应该在出现先行词. 如果前面已经偶一个关系词,就不能用what来引导.例如：You can have everything what you like. what=all that,所以这儿不能用what.
All______ is a continuous supplying of the basic necessities of life
A. what is the need
B. the things need
C. for our needs
D. that is need
2)what单独使用,后面不加名词.
例如：She is not what she used to be.
3)what 后面加名词
例如：What money I have has been given to you.
1997年考题：______he knows about it is out of date and in accurate
A. What little=All that little
B. So much
C. How much
D. So little
as
1. like
2. 作为 As a teacher.
3. when
4. 引导定语从句.即可引导限制性定语从句,也可以引导非限制性定语从句.引导限制性定语从句一般式固定用法.如as…as, such…as , the same as
as引导非限制性定语从句
例如：I was a boy, which you know.which可以用as替换.
As you know I was a boy.
As is so often pointed out knowledge is a two edge weapon which can be used equally for good or evil.
as引导限制性定语从句
考试中往往考固定搭配.
例如：Such is a student as works hard were be sure to succeed.
than作为关系代词可以引导定语从句
More families consist of one parent households or two working parents; consequently, children are likely to have less supervision at home ____ was common in the traditional family structure .
A.thanB.thatC.which D.as
特点：
1) than作为关系代词引导词在从句中一般必须做主语或者作宾语.
2) than 前面的主句必须要有比较级
3) 比较级所修饰的名词就是than指代的对象
给个最佳答案吧,这是我上新东方时做的笔记,希望对你有作用!