Kenneth G. Wilson (1923–). The Columbia Guide to Standard American English. 1993.
LEVELS OF USAGE; USAGE LEVELS IN STANDARD AMERICAN ENGLISH
These phrases describe two different sorts of linguistic variation found in American English. One set of differences involves the distinctions we identify by the labels Standard English, Common English, and Vulgar English, and by the terms Standard English, Substandard English, and Nonstandard English. Each of these sets is a continuum of differences—essentially class differences—in the details of grammar, usage, and vocabulary in both spoken and written English.
Levels of usage can also be used to describe two other continuums of linguistic variation, one representing the levels of our speech, the other the levels of formality (or lack thereof) of our writing (see the figure below, adapted from Gleason [1965]). These schematized five levels of speech and three levels of writing overlap in places, but the differences indicated on each scale are truly significant both in the details of language that are characteristic of each and in the values language users attach to them. In this book, the five levels of speech are named Intimate, Casual, Impromptu, Planned, and Oratorical and the three levels of writing are named Informal, Semiformal, and Formal. Conversational and Colloquial are useful descriptors for a particular cluster of levels (or parts of levels) of speech; Edited English describes a cluster of levels (or parts of levels) of writing. (See Joos 1952; Gleason 1965.)
