If someone asked the question, "Is this answer not right?" would you answer, "Yes, it is not right", or "No, it is not right"?
The problem raised by the question, “Is this answer not right?” highlights one tension between a rule-based understanding of English and a tendency based understanding of the language. Specifically, it reveals an issue with the proscription against double negatives in English, a rule largely imposed on the language rather than one reflecting the tendencies of the language.
While the answer, “Yes, it is not right,” satisfies the prohibition against double negatives and is understandable, for most speakers it would not be as preferable as, “No, it is not right,” which on the surface violates the double negative proscription. The reason for this is that in actual speech in English, this use of two negatives does not constitute a positive or cause confusion. Rather, the first negative intensifies the second, emphasizing that the response is an affirmation that the answer being discussed was not right. Using multiple negatives to emphasize the negative information in an utterance is a tendency in English when the use of the multiple negatives does not lead to confusion whether the utterance is negative or positive.
Interestingly, the use of the negative to emphasize does not work in all instances. Let’s consider another way to phrase the questions:
Is this answer incorrect?
Here, the response should be, “Yes, it is incorrect.” If one were to respond, “No, it is incorrect,” the use of the negative at the beginning of the sentence would create a true double negative situation that would cause confusion.