We can use numbers and a/an with countable nouns; they have plurals.
a cat three cats a newspaper two newspapers Uncountable nouns are the names of materials, liquids, and other things which we do not see as separate objects. We cannot use a/an or numbers with uncountable nouns; they have no plurals.
My father enjoys very good health (NOT . . . a very good health.) We’re having terrible weather. (NOT . . . a terrible weather )
He speaks good English (NOT . . . a-good English )
Also, different languages see the world in different ways. For example hair is uncountable in English, but plural countable in many languages; grapes are plural countable in English, but uncountable in some languages.
Here are some more nouns which are uncountable in English, but countable in some other languages, together with related singular countable expressions.
accommodation a place to live or s
a loaf; a roll a piece of furniture a blade of grass; a lawn a piece of information a fact
a flash of lightning a piece of luggage; a case; a trunk a note; a coin; a sum a piece of news a step forward
a piece of research; an experiment a piece of rubbish a piece of spaghetti a clap of thunder an aching tooth a journey; a trip a job; a piece of work
a piece of advice a loaf; a roll
Note: A headache is countable.
I’d like some white paper (uncountable)
I’m going out to buy a paper (= a newspaper— countable)
The window’s made of unbreakable glass (uncountable)
Would you like a glass of water? (countable)
Could I have some coffee? (uncountable)
Could we have two coffees, please? (= cups of coffee— countable)
For more information about particular nouns, look in a good dictionary.
She’s got red hair. (uncountable)
I’ve got two white hairs. (countable)