On the semantics of when-clauses

This paper is about non-interrogative temporal embedded clauses introduced by when (temporal when-clauses), their semantic interpretation and their syntax/semantics mapping. Our goal is to provide a fully compositional account of temporal when-clauses that accounts for their formal identity with interrogative clauses and their difference in meaning. The main idea is that temporal when-clauses are syntactically and semantically free relative clauses. Previous syntactic analyses (Grimshaw 1977, Bresnan and Grimshaw 1978, a.o) have provided robust support to the syntactic side of this claim. On the other hand, the semantic proposals for temporal when-clauses that we are aware of (Bonomi 1997, Vikner 2004, Moens and Steedman 1988) have ignored these syntactic conclusions and have argued for analyses that are problematic for the syntactic/semantic mapping. These semantic analyses are also not fully adequate in handling the interpretative properties of these clauses. We provide evidence from the distributional and interpretive properties of when-clauses as well as from the temporal alignment of the matrix clause with the when-clause that supports our analysis.