double negative

Any construction in which two or more negative words occur in a single clause.

Examples 1: "I didn't see nothing" (= I didn't see anything);

Examples 2: "No football team can't win no championship without no defenders" (= No football team can win a championship without defenders).

Double negatives are generally discouraged in English because they are considered to be poor grammar and they can be confusing. However, standard English does accept double negatives when both negatives are logically required, as in "You can't not go" (= It is impossible for you not to go).