A double negative is a grammatical construction occurring when two forms of negation are used in the same sentence. Multiple negation is the more general term referring to the occurrence of more than one negative in a clause. In some languages, double negatives cancel one another and produce an affirmative; in other languages, doubled negatives intensify the negation. Languages where multiple negatives affirm each other are said to have negative concord. Portuguese, English, Persian, Russian, Spanish, Neapolitan and Italian are examples of negative-concord languages, while Latin and German do not...