摘要：It is well known that the licensing contexts for Negative Polarity Items (NPIs) and the anti-licensing contexts for Positive Polarity Items (PPIs) are not identical (cf. van der Wouden 1997, Szabolcsi 2004, Homer 2011). In particular, while some NPIs are licensed in every downward-entailing (DE) context (weak NPIs, cf. Zwart 1998), all PPIs seem to be acceptable in the antecedent of a conditional clause and the restrictor of universal quantifiers. This fact opens the possibility that a certain expression be simultaneously a weak NPI and a PPI. Van der Wouden and Nishiguchi (2005) have already suggested that „bipolar items‟ exist. The distribution of such an item would be constrained as follows: it should be able to occur in all NPI-licensing contexts which are not simultaneously PPI-anti-licensing contexts.
