Brazilian Portuguese exhibits three strategies of clausal negation: the standard negative, the double negative and the postverbal negative. This paper is an attempt to describe and interpret specific linguistic properties, which supposedly derive from the use of those strategies by speakers, aiming at inferring the rules that code the discourse function of denial. The negative sentences, analyzed according to the model of competing motivations, are interpreted as the result of the conflict between iconicity and economy. The data come from Corpus Discurso & Gramática - a língua falada e escrita na cidade do Natal.
Negation; Competing motivations; Functionalism; Linguistic change