Are double negatives proper English (e.g. “I don't know nothing”)?

Question

I have heard many (rather most) people, especially in the USA, saying:

I don't know nothing about it.

Is that correct? I always get a weird feeling hearing this and feel the correct one would be saying:

I don't know anything about it.

Answer 1

The second one is correct for most dialects of English. The first one is a double negative, or as we call it in linguistics, exhibits negative concord. Wikipedia has a pretty good article on double negatives:

http://en.wikipedia.org/wiki/Double_negative

Most prescriptive grammarians will tell you that a double negative is incorrect because it is "illogical." However, there are many languages that operate just fine using double negative obligatorily. For instance, almost all Romance languages have obligatory negative concord:

• Italian: Non so niente.
• French: Je ne sais pas.

Double negatives used to be grammatical in English, but there was a grammatical change sometime during Middle English. The Wikipedia article gives a sentence from a 1644 letter by Oliver Cromwell (emphasis is added by me).

A little after, he said one thing lay upon his spirit. I asked him what it was. He told me it was that God had not suffered him to be no more the executioner of His enemies.

The double negative is still used in many modern dialects, but it is typically very stigmatized.

Answer 2

The correct one is the second. The first one might be used, for instance, by the (educated) speakers just in order to give their speach a pleasant rustic flavor. It sounds even better with "ain't" instead of "don't".

Answer 3

The second example is the grammatically correct one.

However, the first is common in certain dialects.

Answer 4

The New Oxford American English reports that anything is used

• in negative, or questions to refer to a thing, no matter what.

  Has she found anything?
  Nobody was saying anything.

• without negative, for emphasis.

  Albert was ready for anything.

Nothing is used in sentences like

She said nothing.
There's nothing we can do.
They found nothing wrong.

Using nothing (which means not anything) in a sentence with a negative is to use a double negation. I imagine the double negation can be used in some particular cases to give emphasis to the sentence.

Answer 5

Logically speaking, the negative of negative is positive.

So, the first sentence may be translated as follows:

I don't know nothing = I know something

Nevertheless, some american slangs use this formula to strengthen the negation not to negate the negation!