I am wondering especially when I travel internationally, some native speakers do not say "a cup of" or "a glass of", for example, "a cup of water” or "two cans of beers". Instead, they sometimes say, "two beers", so naturally I use that myself too because especially to say "a cup of" is, you know, somewhat awkward, so I abbreviate it. Am I correct to understand here? Except for the scenes when we have to emphasize the numbers of the things we would like to buy/want?
I think these "counting prepositions or nouns" (I don't know how I should call them) are the standard English, but personally, it looks like they are dying out.
For example, here in the famous Twin Peaks, Cooper always says, "two cups of coffee", "a cup of joe" (no matter what the size of the cup is, and in the video, he says, "Damn fine, a cup of coffee". Is this polite way to say?). I think after 90's the correct manner has started to die out. Am I right?
Thank you for your answers, people, now, could I summarize like the followings?
These "counting prepositions or nouns or you can name it", are they standard way to express ah, especially ordering or counting things?
Or, there is no consensus at all about this issue. Thus, as words change as time goes, just they are as they are so?