Grammar‏‎ books can generally be divided into two different types: Descriptive or Prescriptive. This article looks at the difference between them.

Very simply, a descriptive grammar looks at what people actually say in real life and then lays out a series of statements describing what is said. With modern technology helping a lot, huge collections of language examples have been made and analyzed using programs known as concordancers‏‎. These have found certain patterns in modern English‏‎.

A prescriptive grammar, on the other hand, looks at language from a much more academic perspective. Learned people have sat around tables and decided that regardless of what happens in real life they will produce a series of rules about how to use English correctly.

You Don’t Know Nothing

For example, if you do a search on Google for the exact phrase, “don’t know nothing” (see links below) it comes back with over 70 million hits. That means people have written and used the phrase a great deal online. A descriptive grammar might look at this and say that since so many people are obviously using this phrase it is a very common grammatical occurrence and therefore it must be correct.

However, learned people have always said that double negatives‏‎ are wrong and ungrammatical in English and therefore the phrase, “don’t know nothing” is not correct English at all and it is a mistake to use it.

Who is Right?

It may sound as though there are two completely separate schools of thought when it comes to grammar, however this is not the case. It is actually a continuum from the most conservative of prescriptive grammarians right through to the most liberal of descriptive grammarians.

A very traditional prescriptive grammarian will insist that splitting infinitives‏‎ is wrong. A liberal descriptive grammarian thinks they are fine. And in the middle is a grammarian who might think splitting infinitives is fine but double negatives are wrong.

Generally speaking as language teachers we should follow the consensus. Most people feel that double negatives are wrong so in class we should teach this. But we should also remember that language is fluid and ever changing. Thirty of forty years ago the use of a masculine pronoun‎ to talk about men or women was almost universal:

You can make an appointment with your doctor over the phone but be sure to tell him if you need to cancel.

Nowadays, however, it seems old fashioned and “wrong” and instead many people will use a gender neutral pronoun:

You can make an appointment with your doctor over the phone but be sure to tell them if you need to cancel.

Perhaps then in thirty or forty years time the use of double negatives in English will be so common that we will teach them!

Useful Links

Split Infinitives‏‎ in English Grammar – a bone of contention

Double Negatives‏‎ in English – another bone of contention

Double Negatives on Google – how many double negatives on Google?