what可以用來引導定語從句嗎

what不可以用來引導定語從句.

what可以用來引導主語從句、賓語從句、表語從句、同位語從句等。

例句：

1、What you did was quite right.

what引導主語從句。

2、I didn't hear what you said clearly.

what引導賓語從句。

3、This was what he had bought.

what引導表語從句。

4、I have no idea what he has done.

what引導同位語從句。