Quantification and polarity: negative adverbial intensifiers ('never ever', 'not at all', etc.) in Hausa

Hausa has a typologically interesting but poorly understood set of quantifying time and degree adverbs—equivalent to English 'never ever', 'not at all', etc.—which behave as negative polarity items and enhance the pragmatic impact of a negative utterance (both verbal and non-verbal). The functional distribution of these adverbial intensifiers is unusual, however, in that some are "bipolar", i.e., they can express opposite (minimal/maximal) values according to whether they occur in negative or positive syntactic environments, with the minimal intensifiers operating at the negative pole. An intensifier such as dàɗai, for example, can mean either 'never' (negative) or 'always' (positive), and other modifiers, e.g., atàbau, can express these same temporal meanings in addition to 'absolutely'. This paper provides a unified account of this natural functional class of adverbs, and is seen as a contribution to cross-linguistic research into polarity items and their licensing contexts