Descriptive vs Prescriptive Grammar: A Simple Explanation

One word that comes up all the time, both in everyday discussions of language and among linguists, is grammar. What is grammar? Grammar is a term we use to describe the rules that describe how a language works as a system.¹ It tells us how words and sentences are constructed. The grammar of English, for example, is what tells you that, in the sentence Dogs chase cats, dogs are doing the chasing and, in the sentence Cats chase dogs, that the tables have turned, and the cats are the ones chasing the dogs.

Prescriptive grammar

The word "grammar" also has an ordinary, non-technical meaning that many of you may know. Have you ever heard someone tell you that "ending a sentence with a preposition is bad grammar"?

Let's dwell on this for a moment, because it leads to lots of misconceptions about linguistics. For example, in English we have the following two sentences:

1. Who did you talk to?
2. To whom did you talk?

Both mean the same thing, in the sense that they're both questions asking you to identify the person you were in a conversation with. And if you're a speaker of English, you can likely just as easily understand either of the two. But the sentence Who did you talk to? and others like it often get criticized as using "bad English grammar".

On the linguistic view, this doesn't make sense. For a linguist, a grammar is a system that lets us associate form and meaning. If an English speaker produces the sentence Who did you talk to?, and an English speaker understands it, how can that sentence be contrary to English grammar? The form and meaning have been successfully linked, have they not?

The everyday use of the word "grammar" refers to something else entirely: the system of rules for one particular, high-prestige variety of English. In this variety of English, To whom did you talk? is the preferred way to express the meaning which might just as well have been expressed with Who did you talk to?. In linguistics, we call this kind of grammar a normative or prescriptive grammar. As linguists, we don't spend a great deal of time worrying about prescriptive grammar.

Descriptive grammar and grammaticality

Let's compare this prescriptive dichotomy of "good vs. bad grammar" with a more descriptive one: "grammatical vs ungrammatical".

3. Who did you talk to? (grammatical)
4. *To did you who talk? (ungrammatical)

In the grammatical sentence, everything is fine and we can complete the association between form and meaning. Or, in other words, this sentence is part of the English language. In the ungrammatical sentence, we cannot complete the association of form and meaning. It comes out as "word salad". English words jumbled up in an order that makes no sense in the grammar of English.

When we study the grammar of a language, what we're often interested in doing is working out the principles which let us distinguish between these two types of sentences.

This is the descriptive grammar that linguists are interested in. As linguists, we are not trying to judge any form of language as better or worse, just reporting what we find in our investigations. This is a natural consequence of the fact that linguistics is the application of scientific methods to the study of language. Science can tell us what's going on but it can't tell us what we should do.

Footnotes

1. If you're curious about what I mean by "working as a system", read my article on how linguists look at language first. ↩