Double negation is a grammatical construction where two negative words are used in the same sentence, often leading to a positive meaning. For example, in the sentence "I don't know nothing," the two negatives ("don't" and "nothing") can cancel each other out, suggesting that the speaker does know something. This phenomenon is common in various dialects and languages, but it can create confusion in standard English. In formal logic, double negation refers to the principle that negating a negation returns to the original statement. For instance, if we say "It is not the case that it is not raining," this implies that it is indeed raining. This principle is foundational in mathematics and philosophy, helping to clarify arguments and reasoning.