Regional dialects vary in their words, pronunciation, and grammar.
There are 18 early American population centers which retain a distinct dialect, representing main colonial settlements where mobility was limited for the first generations. The eastern half of the U.S. can be divided into four distinct dialect areas. The film contrasts these four distinct areas, together with two of the eastern population zones. Shifting patterns are the rule in American English. Some features may be isolated or peculiar to one regional dialect, but most are found in nearly all, or at least are recognized by all.