many用来修饰复数可数名词，表示许多的意思，与few（少数）的意思相反。而much则用来修饰不可数名词，表示量或是程度，与little（少量）的意思相反。
如：How many people are there in your family? 你们家有几个人？
How much money did you spent on it? 你在这上面花了多少钱？
many和much都可以与more连用，但区别在于many more之后接复数名词，much more之后接不可数名词。
如：There have been many more burglaries this year.今年盗窃案比过去多好些。
His car cost much more money than mine.他的小汽车所花的钱比我的多得多。
much可以用在形容词、副词的比较级之前，但是many不可以。
如：Many of them were very tired.I don't eat much for lunch. 〔代名词)
He is much taller than I. (副词〕