This paper discusses the behavior of negative pronouns in a generative framework. It intends to account for their possible word order, as well as their interpretation and prosody (stressed vs. unstressed occurrence) in the various positions. The generative theory of language maintains that word order, semantic interpretation and prosody are all dependent on syntactic structure. What we have to determine, then, is the structural position of negative pronouns. - The main claims of this paper are as follows: se-pronouns are quantifiers left- or right-adjoined (Q-raised) to NegP, subjected to negative concord. In the preverbal part of the sentence, their word order automatically follows from their syntactic position (they are left-adjacent to the negative particle). When right-adjoined to NegP, they participate in optional reordering in he phonological component. They carry stress except when occurring within the scope of focus or negation in their surface position; in the latter case, they are destressed. They are universal or existential quantifiers (depending on their specificity feature). The particle sem 'neither' is ambiguous: it may represent the negative particle, or else it can be a 'minimalizing modifier', the counterpart of is 'also' in a negative context. Sem functions as a negative particle if no other negative particle occurs in the portion of the sentence that precedes it.