AHD
Introduction. The American Heritage Book of English Usage. 1996
Standard English Standard English is the language we use for public discourse. It is the working language of our social institutions. The news media, the government, the legal profession, and the teachers in our schools and universities all aim at Standard English as a norm of communication, primarily in expository and argumentative writing, but also in public speaking. Standard English is thus different from what we normally think of as speech in that Standard English must be taught, whereas children learn to speak naturally without being taught. Of course, Standard English shares with spoken English certain features common to all forms of language. It has rules for making grammatical sentences, and it changes over time. The issues of pronunciation discussed in this book mainly involve how to pronounce specific written words or written letters, such as ch or g, in different words. The guidance to pronunciation is not meant to standardize or correct anyone’s naturally acquired form of spoken English.
The name Standard English is perhaps not the best, since it implies a standard against which various kinds of spoken English are to be measured, and this is hardly a fair comparison. A better name might be Institutional English, Conventional English, Commercial English, or Standardized English for Writing and Public Speaking, but these names all have their own negative connotations and shortcomings. So, since Standard is what this brand of English has been called for generations, we use the name here.
Nonstandard English There are many expressions and grammatical constructions that are not normally used in Standard English. These include regional expressions, such as might could, and other usages, such as ain’t and it don’t, that are typically associated with dialects used by people belonging to less prestigious social groups. These nonstandard varieties of English are no less logical or systematic than Standard English. In this book an expression labeled nonstandard is not wrong; it is merely inappropriate for ordinary usage in Standard English.
Formal English On some occasions it is important to adhere to the conventions that characterize serious public discourse and to avoid expressions that we might use in more casual situations. Formal writing and speaking are characterized by the tendency to give full treatment to all the elements that are required for grammatical sentences. Thus in formal English you might hear May I suggest that we reexamine the problem? where both clauses have a subject and verb and the subordinate clause is introduced by the conjunction that. Of course, formal English has many other features. Among these are the careful explanation of background information, complexity in sentence structure, explicit transitions between thoughts, and the use of certain words such as may that are reserved chiefly for creating a formal tone. Situations that normally require formal usage would include an article discussing a serious matter submitted to a respected journal, an official report by a group of researchers to a government body, a talk presented to a professional organization, and a letter of job application.
Informal English This is a broad category applied to situations in which it is not necessary, and in many cases not even desirable, to use the conventions of formal discourse. Informal language incorporates many of the familiar features of spoken English, especially the tendency to use contractions and to abbreviate sentences by omitting certain elements.
Where formal English has May I suggest that we reexamine the manuscript? in informal English you might get Want to look this over again? Informal English tends to assume that the audience shares basic assumptions and background knowledge with the writer or speaker, who therefore alludes to or even omits reference to this information, rather than carefully explaining it as formal discourse requires. Typical informal situations would include a casual conversation with classmates, a letter to a close friend, or an article on a light topic written for a newspaper or magazine whose readership shares certain interests of the writer.