English is a world language. Perhaps as many as 400 million people speak it as their first language; over a billion speak it as a second language.

The ability to speak and write a standard, easily-understood form of English is a valuable tool for all Americans.

Knowing more than one dialect is useful

Accented English

American dialects

Dialect vs Accent

Being able to use a standard form of English when the occasion calls for it is a useful employment skill.

Clear, understandable speech is a social asset:

M. J. Maddox, PhD 
is the American English Doctor.