Supplemental relative clauses: Internal and external syntax

Abstract

The internal syntactic structures of restrictive and non-restrictive relative clauses are largely identical. This paper argues that despite a uniform internal structure, the external distributions – specifically, linearization with respect to the head – of non-restrictive relative clauses are subject to several conditions. In particular, sentential non-restrictive relative clauses with which and what can appear to the left of their heads in limited (and distinct) syntactic contexts. These lexical and syntactic constraints are represented within the framework of Sign-based Construction Grammar. In light of these observations, the paper revisits claims about the internal structure of parenthetical as-clauses. Prior claims that as cannot be a relativizer are shown to be unfounded, and new data are presented in favor of treating them as relative clauses with the external distribution of sentential adverbials. This is possible given the ability to state separately specifications of construction-internal syntactic structure and construction-external linear-order constraints.