Considerable attention has been paid to the system of negation; nevertheless, the study of negative polarity has not been conducted from the perspective of translation. This paper concentrates on some of the problems that the translation of some English negatives may pose for Spanish speakers. It starts by showing the ambiguity of some negative constructions in English as well as the contradictions that may be detected between the syntactic, semantic and even pragmatic levels of the language with regard to polarity. It then goes on to examine the scope of negation in both English and Spanish as well as its implications in the field of translation. This section also includes a careful analysis of the negation of English auxiliaries and of the so-called transferred or raised negative constructions. Part three is concerned with double negation in both standard and non-standard English, while part four deals with the definition and anticipated difficulties in the translation of negative polarity idioms (NPIDs).