I attended his lecture,most of what he said had nothing to do with my subject,though.

题目

I attended his lecture,most of what he said had nothing to do with my subject,though.
这是定语从句吗?为什么用what?

答案

这不是定语从句,是“所”字结构
这里what表示“所”的意思,
我参加他的演讲会,大部分他所说的 对我的课题没有帮助