Understanding Prescriptive vs. Descriptive Grammar

When people hear about linguistics, they often believe that linguists are very much like the character Henry Higgins in the play My Fair Lady, who expresses sentiments like in the following song, where he bemoans the the state of English and the lack of proper pronunciation:


However, as you will learn in this first week of class, there are two different ways that language has been talked about in disciplines that focus on the use of language. We can talk about these different approaches to language as descriptive grammar vs. prescriptive grammar. 

Prescriptive grammar  describes when people focus on talking about how a language should or ought to be used. One way to remember this association is to think of going to a doctor’s office. When a doctor gives you a prescription for medication, it often includes directions about how you should take your medication as well as what you should not do when taking your medication. In a similar way, a prescriptive grammar tells you how you should speak, and what type of language to avoid. This is commonly found in English classes as well as other language classes, where the aim is to teach people how to use language in a very particular (typically described as ‘proper’ or ‘correct’) way.

Descriptive grammar, on the other hand, focuses on describing the language as it is used, not saying how it should be used. For example, think about a prescriptive rule like Don’t split infinitives. A descriptive grammarian would see a sentence like “To boldly go where no man has gone before” and would try to describe how the mental grammar can cause that ordering of words, rather than saying that the surface form is faulty due to prescriptive rules (which would require the sentence “To go boldly where no man has gone before”). Linguistics takes this approach to language.

A key contrast is to be found between these two approaches. A descriptive grammarian would say that a sentence is “grammatical” if a native speaker of the language would produce that sentence in speaking. The descriptive grammarian would then try to describe how that sentence is produced through theorizing about the mental processes that lead up to the surface form. A prescriptive grammarian, on the other hand, would say that something is grammatical only  if the surface form conforms to a set of rules that the grammarian believes should be followed in order for a certain grammar style is achieved. (Note that I have tried to emphasize that the descriptive grammarian hears a form and tries to describe the mental processes underneath the produced (spoken) form, while a prescriptive grammarian does not hypothesize about the mental grammar at all, but is merely concerned with ‘editing’ the surface form.)

Again, Linguistics aims to provide a descriptive grammar of language. In this course, we will use data based on surface forms (i.e. ‘spoken’ or ‘produced’ data) and will try to describe how these surface forms occur through processes in the mental grammar.