What如何引导定语从句?

what = the thing/things that,因此what可以用于定语从句,但不需要先行词,换句话说,what其实引导的是名词从句。比如：This is what I want。= This is the thing that I want。这就是我想要的。Do you know what they're doing?= Do you know the thing they're doing?你知道他们在做什么吗?What caused the accident were stones。= The things that caused the accident were stones。一些石头导致了这起事故。