I want a Coke, I want Coke?

Hi,

As I know, Coke(Coca-Cola) could be an uncountable noun,

but I saw the phrase "I want a Coke",

Is it right?

It means "Coke" could be a countable noun, too. Yes. You can sit in a restaurant and order a Coke, or 3 Cokes. Or 3 Pepsis. Or 3 Budwei

Yes, in restaurant (or other food and drink) situations, you can talk about usually uncountable nouns that way.

I want a Coke means I'd like a bottle of Coke, or a glass of Coke. The same with coffee or water or other similar things.

So can you think what "Three coffees, a Coke, and we'd each like a water too, please" means when you say it to y

Yes, your are right! It could be a countable noun too only when you don't want to use measure words like cups or cans or glasses in front of food names or drinks and so on. So instead of saying, I want a can of coke you can say I want a coke. Instead of saying, I want a cup of coffee you can say I want a coffee.

English grammar can be very confusing in some situation or lea