I've got about three minutes here before I'm off to work, so this is cursory. Your own corpus cite, JTT, shows that in fact "may" DOES" function for permission, as I contended. May be not that common, but it certainly does. never said otherwise, and for people who use it they're most likely following the prescriptive rule , which functions AS A RULE FOR THEM IN THEIR CHOICE OF LANGUAGE, as I've maintained all along.
And on another topic you've brought up, you say
Quote:
People operating naturally in language can't and don't follow prescriptions because "prescriptions are alien to the natural workings of language".
Nonsense. Language is a social construct. Social constructs operate by any number of prescriptive rules. Language is no exception. Test it. The next dozen people you meet, say "******* glad to meet you". The next dozen times you use a sentence with a negative in it, use a double negative instead. Note the reactions. Be careful you don't get your block knocked off in the former. There are prescriptive rules against those usages, which people DO follow. Anyone who contends otherwise does not live in the real world. Your anonymous citee is apparently one of those people.