Both prescriptivists and descriptivists often make statements about whether or not a particular utterance is grammatical. For a prescriptivist, deciding that an utterance is ungrammatical is the first step in eliminating error. For a descriptivist, observing what native speakers do not do gives important clues to understanding the tacit rules of the language. But given the difference between descriptive and prescriptive rules, we have to be careful to specify what kind of grammar we have in mind.

The consequences of these clashing assumptions are nowhere more stark than in the confusion over the term grammar, which has various, somewhat conflicting meanings depending on who uses the term. Grammar, at its core, refers to the rules of language. But how these rules are imagined and what these rules encompass can vary greatly from definition to definition. As a result, the common understanding of grammar differs in subtle but important ways from the linguistic sense of the term.

The traditional understanding of grammar—the one we associate with the prescriptivist position—began in ancient Greece and Rome. For hundreds of years, grammar was synonymous with the study of Greek and Latin.[1] These languages were regarded as perfect—or nearly so—and their grammatical structures were taken to be universal forms by which all "vulgar" languages should be judged. It was not until the seventeenth century that writers began to turn their attention systematically to the grammar of English itself, and when they did so, they applied the structures that they had learned studying classical languages to English.

Linguistics takes a descriptive approach to language: it tries to explain things as they actually are, not as we wish them to be. When we study language descriptively, we try to find the unconscious rules that people follow when they say things like sentence (1). The schoolbook approach to language is typically prescriptive. It tries to tell you how you should speak and write.

Notice that there is a place for both description and prescription in language study. For example, when adults learn a foreign language, they typically want someone to tell them how to speak, in other words to prescribe a particular set of rules to follow, and expect a teacher or book to set forth those rules. But how do teachers know what rules to prescribe? At some point in time, someone had to describe the language and infer those rules. Prescription, in other words, can only occur after the language has been described, and good prescription depends on adequate description. We obviously don't want to be teaching people the wrong things about language.

Children can learn any language they are exposed to. Take a moment to consider how remarkable that ability is. If you put any infant born without developmental disabilities in any culture, that child will learn the language—or languages—he or she hears spoken. Ethnic origin makes no difference to this fluency. A child of Japanese parents raised by English speakers will grow up speaking fluent English. A child of European ancestry will learn to speak perfect Navajo if raised among Navajo speakers. And no special training is necessary. By the time children reach school age, they have already mastered the basic structures and vocabulary of their native language, even if their parents give them no special instruction.

This work is under construction, and has been for a long time. There are parts that have been written but not converted for the web, and others that remain to be written. As of 2020, after a long hiatus, I'm putting in more time to fleshing out this work, but I have limited time to spend on this project and tend to work on it in spurts, so there are no guarantees that it will ever be done.

(Last updated 7 Jan 2020)