On flteach many years ago a teacher related how a colleague Sp teacher travelled to Mexico and marveled how well educated even the hotel maids were b/c they all used the subjunctive. Re the subjunctive in English, it has died out in Britain but is still used in the U.S. I have made many notes over the years of uses of the subjunctive and tried to get the educational level of the speaker; I am not sure subjunctive use is tied to education level. After all, it is part of the basic grammar of English and therefore well-nigh unteachable, so it as to be acquired as part of first language acquisition. (re comparison of subjunctive and other grammatical features usage between U.S. and Britain, see Brinton and Arnovick, History of English; nice comparison chart toward the back.