Both are perfectly acceptable in English. Common drinks like tea, water, pop (soda), can be used without "a" as a non-count noun, or with "a" to indicate "a (cup/glass of) X." If you throw in an adjective the context becomes a bit clearer. At a coffee show "I'm going to grab a coffee, would you like a tea?" or "another tea". Or "Yes, I'd like a large tea." etc.
ChrisWhatever, Yes, where I come from, too - but mostly only in the winter. It is very hot here in the summer, so we offer a GLASS of (Iced) Sweet Tea, or just say, "You want some tea?"
BTW, I asked the question above the way I would naturally, except added the "a" when I noticed it, and Duo didn't accept "You want a tea?" In casual conversation, it is correct for the "Do" to be understood without speaking it.
Well darn it! Reading through these comments makes me wonder if I'm the only English speaking person who quite happily goes into the kitchen saying to my husband, "I'm making myself a tea, do you want a tea?". I also order "a tea" in a restaurant/cafe, so to me, none of these phrases seem odd...
Mwahahhaha.... More evidence the world revolves around ME !!!
No need to use such language there are kids here too, I myself am only 13 and I already am using better language than you. If you want to use such words then can do it where they isn't any kids reading your comment, who knows they might even say it in front of their parents/guardians. Please next time you eant to use such language then you can go ahead and leave the comments section and continue learning Spanish, or you might as well learn some English too while your at it because your grammar seems to be really bad. Thank you, and remember that you can just leave the comment section if you want to use such language! :)