兩者都表示“許多”，但 many 修飾或代替復數(shù)可數(shù)名詞，而 much 用來修飾或代替不可數(shù)名詞：

　　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 of us left early. 我們有許多人離開得很早。

　　Much work has been done. 許多工作都已經做了。