* "Amount" is used for things that cannot be counted individually. For example: a large amount of water, a large amount of sand, a large amount of money.
* "Number" is used for things that can be counted individually. For example, a large number of people, a large number of cars, a large number of books.
Alternatives:
* Large quantity: More formal and often preferred for tangible objects.
* Substantial amount: Implies a significant amount.
* Considerable amount: Similar to substantial, but can be used for both tangible and intangible things.
Example:
Instead of saying "There was a large amount of people at the concert," you could say:
* There was a large number of people at the concert.
* There was a substantial quantity of people at the concert.
* There was a considerable amount of people at the concert.
The best choice will depend on the context and the level of formality you're aiming for.