A Grammar Lesson
Amount & Number

People generally acquire their first language through exposure to the language over a long period of time. They hear the language spoken by the members in their environment and the media; they don’t spend much time studying the rules of the language.
If and when people learn a second language, though, they study the grammar of that language to make sense of its rules.
I hear and read people whose first language is English use the word “amount” with countable nouns, like people and books, and all I can think is they have probably heard a large number of people misuse it and they haven’t learned its correct usage.
Every English-speaking person, particularly writers and public speakers, should know this grammar rule, so I’ll make this as concise as possible, hoping everyone finds the time to read it.
The word “amount” is used as a quantifier (a word which indicates how much) with uncountable nouns.
the amount of coffee
a large amount of information
a small amount of olive oil
a considerable amount of bread
half the amount of sugar
The nouns coffee, information, olive oil, bread, and sugar are all uncountable, so only quantifiers for nouns that can’t be counted (much, little, a little, amount of) should be used with them.
&
The word “number” is used as a quantifier (a word which indicates how many) with countable nouns.
the number of cups of coffee
a large number of books
twice the number of oranges
a small number of people
a huge number of small pies
The nouns cups, books, oranges, people, and pies are all countable, so only quantifiers for nouns that can be counted (many, few, a few, a number of, several) should be used with them.
Thanks for reading.