Semantics of finite complement clauses and scope islandhood

This paper investigates the correspondence between the semantics of a finite complement clause and its scope islandhood. Via comparison of the semantics of canonical attitude verbs, e.g. believe and claim, with that of clause-embedding verbs like ensure and prove, whose complement clauses are not scope islands (Farkas and Giannakidou 1996, Barker 2022, Palucci 2024, a.o.), this paper argues for two claims. First, while complement clauses of attitude verbs have been argued to denote predicates of individuals with propositional content (Kratzer 2006, Moulton 2009, 2015, Elliott 2020, a.o.), those of ensure-type verbs denote predicates of events (without propositional content). Second, finite complement clauses that denote predicates of events are not scope islands.