Hwat for what is the original pronunciation and was the only form used in Middle English. In Modern English, many dialects lost the wine-whine distinction, and began pronouncing words spelled "wh" as simply "w", rather thn "hw". The original,

#2 is not correct. "When dialects diverge to the point that they are mutually incomprehensible, they become languages in their own right" That is not always the case. For example, "Chinese" dialects are mutually unintelligible, but "Chinese"

So what's your definition of American English (or North American English, as some prefer)? I would probably define it mostly by its phonology. It would be pretty hard to define. Or why not just say, any dialect of English spoken in North