Some things you can count but other ones you cannot.
That’s the reason you have to be careful when using “many” or “much”, for instance. Let me make it clear: some words can only be used with things you can relate to a quantity, i.e. a specified amount.
So you want to use indefinite quantifiers – words you put in front of a noun which are not quantities but represent “how much” it is – but you are not sure when to use them?
It’s easier than you think.