[Ivan N]

The variety of English spoken in the USA has received the name of
American English. The term variant or variety appears most appropriate
for several reasons. American English cannot be called a dialect
although it is a regional variety, because it has a literary normalized
form called Standard American, whereas by definition given above a
dialect has no literary form. Neither is it a separate language, as
some American authors, like H. L. Mencken, claimed, because it has
neither grammar nor vocabulary of its own. From the lexical point of
view one shall have to deal only with a heterogeneous set of
Americanisms.