CarolC, I agree. Rap and other forms of Af-Am popular music are spreading AAVE, not only to non-African-Americans, but to African-Americans far from the population centers where it is well-known. A few African-Americans here, in western Canada, are trying out a bit of that vernacular, albeit with grins and somewhat self-conciously. Their origins are Caribbean and African, without backgrounds in the United States.

Dialect in America was well-understood by Mencken, and English writers as well, but the statement was true that the dialects were understandable and formed part of a common language. Randolph may have found a few pockets of dialectical extremes, but there is nothing of the problems that would have faced an American, regardless of his regional origin, who was trying to understand Glaswegian. Especially since the WW2 era, dialects in North America have lost their meat, although the 'trimmings' remain. I am sure that since WW2, dialects in Great Britain also are less pronounced, and, as Leeneia suggests, "all English speakers speak a common language ... might have to slow down a bit..." My own experience in parts of the British Isles 50-60 years ago would argue against this having been the case in parts of northern England and parts of Scotland at that time. Speaking of that time, I would agree with Mencken that "English is more emphatically one in America than in its native land"

Azizi, is the type of African-American vernacular in the music and on the street partly based on an attempt to develop communication that is apart from that of white 'standard' culture? You may have answered this before.