He is a man of great knowledge,from whom much can be learned这里的much作什么用?

问题描述:

He is a man of great knowledge,from whom much can be learned
这里的much作什么用?

这里的much是不定代词 作定从中的主语

It is a noun, used as a subject.

much是从句的主语
from whom much can be learned是从句
from whom在从句中作状语
can be learned在从句中作谓语