True, it is the cups that is supposed to take the plural, but when was the last time you ordered "three large cups of coke" and not "three large cokes".
Yes, I am an English teacher*, and it is true that the grammar books say coke can't be plural, but people look at you funny today if you say it correctly. It is assumed you are talking about the cups right?
Yes, formally it is incorrect, but when the size is predetermined, that size becomes a countable noun and the noun the size refers to is often dropped from the sentence.
Or am I totally messing this up. Keep in mind I'm teaching something closer to EFL than ESL. English that my students can use to be understood on their two week home stays and trips to New York. Not long term living English.
I still think that adding a size adjective makes it into a countable noun though.
Though I need to look it up. Some other grammar magic may be happening than what I'm seeing and my grammar vocabulary is woefully lacking. I know it better in Japanese than I do in English at this point.
I should put more smileys in there, the above probably reads a whole lot harsher than intended. No harshness should be in there at all.
*technically. I'm one of those guys who came to Japan with absolutely no training and they say, "Hey, you are a native English speaker, teach English for us. Here, we'll pay you this <obsene amount of money for someone with no training or certification> to do it. You start on Monday, we already have 12 classes a week lined up. Oh, here is the text book the previous teacher used. Tell us if you have any problems."