Hello! This type of phrasing is called a double negative and is considered grammatically incorrect. It is called a double negative because there are two words with a negative meaning in the sentence: "not" and "no". For the sentence to have a negative meaning, we can only use one: "He's not buying a car" would be most natural. Even though double negatives are grammatically incorrect, they are used in some dialects of English; for example, some people in the Southern United States may say "He's not buying no car." I hope that helps!

Agree with Sarah; the double negative is technically grammatically incorrect and the correct answer would be “he’s not buying a car.” But it can be used (informally) to emphasize a point or to be sassy, or it may be used in certain dialects. Even more informal would be to say “he ain’t buyin’ no car!” - to emphasize that he is definitely not buying any car... I would suggest using that one only with friends in informal situations, especially while still learning English. Hope that helps!

I agree with Sara and Michelle that double negatives, in general, are grammatically incorrect. I would only use this in very informal situations and to be funny. Double negatives cancel each other out and make the statement positive, which can be confusing. Technically, “he’s not buying no car” would mean he actually is buying a car.

There is nothing we can't fix :) . There is nothing gramatically incorrect about a double negative. Using it as if it were still a negative, that's a mistake. Technically not buy no car = buying a car, or more. . Hence the answers below are right in that this is not good language, but a common mistake or used for emphasis, sometimes. .

Hello! Please see my answer below. I hope it helps!