上节课我们讲到，特殊疑问句变成名词性从句，其中有what引领的从句，我们先整理一下：
What should I do next?
下一步我该做什么呢？
what引领的名词性从句
What I should do next is not clear yet.
下一步我该做什么还不清楚。
接下来，我们要讲一讲what也可以作复合关系代词。什么是复合关系代词：
复合关系代词是由两个词类复合而成：一方面含有先行词,如anybody,the thing,anything;一方面又含有关系代词，如who,whom,which。
好复杂，你只要记住，what=the things(s) which, 这两者可互换，意思对比即可，都解释为“所......的东西”。也可以用在名词性从句中。
作主语时What I should do next is not clear yet.
=The thing which I should do next is not clear yet.
下一步我该做什么还不清楚。
作宾语时
I don't agree with what you've said to me.
=I don't agree with the words you've said to me.