两者都表示“许多”，但 many 修饰或代替可数名词（复数），与 few（少数）相对；而 much 用来修饰或代替不可数名词（单数），与little（少量）相对。much 除了是限定词外，还可以是名词或代词，可以充当句子的主语和宾语。many修饰可数名词和不可数名词，后面要用复数名词。
相关介绍
It was many years before the full story was made public.
许多年之后，事情的全貌才公之于众。
We'd like as many people as possible to attend.
我们希望出席的人越多越好。
Do you have much money left?
你剩的钱多吗?
He doesn't spend much time preparing his lessons.
他备课不花太多时间。
