Coffee

[Xinfu]

Could I use a? (rather than leaving it blank)

-She was drinking __ coffee.

Some people think coffee is a substance, then no a/an should be used. But my opinion is different: in modern English, very often in a restaurant we say a juice, a coffee, etc., to mean a cup of sth; I see no problem in the sentence above. Who is the correct one?

[Rusty]

Both 'a coffee' and coffee without the article are correct.
You have understood the difference well.

[Xinfu]

Excellent answer. Thank you.