many用來修飾復數可數名詞，表示許多的意思，與few（少數）的意思相反。而much則用來修飾不可數名詞，表示量或是程度，與little（少量）的意思相反。
如：How many people are there in your family? 你們家有幾個人？
How much money did you spent on it? 你在這上面花了多少錢？
many和much都可以與more連用，但區別在于many more之后接復數名詞，much more之后接不可數名詞。
如：There have been many more burglaries this year.今年盜竊案比過去多好些。
His car cost much more money than mine.他的小汽車所花的錢比我的多得多。
much可以用在形容詞、副詞的比較級之前，但是many不可以。
如：Many of them were very tired.I don't eat much for lunch. 〔代名詞)
He is much taller than I. (副詞〕