Observing the distinction between Standard and nonstandard English

Standard English is the language used in all academic, business, and professional fields. Nonstandard English is spoken by people with a common regional or social heritage. Although nonstandard English may be appropriate when spoken within a close group, it is out of place in most formal and informal writing.

If you speak a nonstandard dialect, try to identify the ways in which your dialect differs from Standard English. Look especially for the following features of nonstandard English, which commonly cause problems in writing:

You might also scan the Glossary of Usage, which alerts you to nonstandard words and expressions such as ain’t, could of, hisself, theirselves, them (meaning “those”), they (meaning “their”), and so on.