4）what（相当于一个先行词或者作为自己的先行词）
也就是说如果一个句子中有先行词，那就不能用what来引导
例如：you can have everything what you like.（错）
(从语法上讲what=all that)
替换：you can have everything all that you like.
(everything与all重复，所以句子表达错误)
正确：you can have everything that you like.
she is not what she used to be.她现在已不再是过去的她了
what做she used to be的宾语，此处做后面句子的宾语，同时做
前面句子的宾语，只有what才能满足。
used to be过去常常做
be used to doing习惯于做某事
what money (that) i have has been given to you.
关于理解，怎么通顺怎么理解.
5）as(1.=like 2.作为 3.当...的时候 4.定语从句)
引导限制性定语从句和非限制性定语从句
1.引导先执行定语从句是固定用法
such a student as works hard well be shure to succeed.
2.引导非限制性定语从句没有固定用法
i was a boy which(=as) you know.=AS you konw i was a boy.
注：完形填空中常考，明明是非限制性定语从句放到句子后面由which
来引导，当强行把这个非限制性定语从句放到句子前面的时候
需要把which改成as，不能用which引导定语从句放到开头，这是规定.
楼主
