你的问题问大了.
如果作为副词使用,后面可以跟单数名词,也可以是复数名词
I think much / little of it / them
I think much / little of this book / these books.
如果作为主语/宾语,后面可以跟单数名词,也可以是复数名词
Much / little of the factory / factories was known to us then.
如果后面只能是不可数名词,much / little强调这个名词的量;
Much / little of the work has been done so far
全看你怎么理解了.英语的基本功是关键.