Head-Based Syntactic Identity in Sluicing

This article puts forward two distinct arguments regarding the condition on identity between antecedent and ellipsis site that governs the grammaticality of sluices. The first argument is that the viability of a requirement of syntactic identity has been too hastily dismissed. Such a condition is viable if syntactic identity is not assessed over the entire deleted constituent, but instead is assessed head-by-head for each head stranded in the ellipsis site. This allows syntactic differences associated with material that has moved out of the ellipsis site to not affect the calculation of syntactic identity. The second argument is that the bestiary of possible mismatches under sluicing can be given a uniform syntactic characterization: all and only material originating outside of the verbal complex can be mismatched under sluicing. The restriction of identity conditions to the verbal complex is implementable in many (but not all) approaches to ellipsis identity; I provide a concrete application of it to the proposed head-based syntactic identity condition.