Optimal interleaving: Serial phonology -morphology interaction in a constraint-based model

This dissertation proposes a novel theory of the phonology-morphology interface called Optimal Interleaving (OI). OI is based on Optimality Theory with Candidate Chains (OT-CC), which is proposed by McCarthy (2007a) as a serial architecture for Optimality Theory (Prince & Smolensky 2004 [1993]). OI adds to OT-CC the hypothesis that morphological spell-out (Halle & Marantz 1993\u27s \u27vocabulary insertion\u27) occurs in the phonological component of the grammar. OI thus allows phonological and morphological operations to be interleaved in a fashion similar to that assumed in the theory of Lexical Phonology (Kiparsky 1982a,b, Mohanan 1982). Chapters 2 and 3 argue that OI makes a number of correct predictions about phonologically-conditioned allomorph selection. Chiefly, OI derives the empirical generalization that allomorph selection is always opaque with respect to phonology conditioned by the competing allomorphs (Paster 2005, 2006, to appear). It does so while keeping phonologically-driven allomorphy in the phonology and governed by phonological constraints. OI therefore avoids a version of the Duplication Problem (Clayton 1976) which is faced by theories which derive the opacity generalization by attributing all allomorph selection to subcategorization in the morphology (Paster 2005, 2006, to appear; Bye 2007). Chapter 4 shows that OI, and more generally OT-CC, can be applied to non-derived environment blocking (NDEB: Kiparsky 1973a). It is shown that OI makes five correct predictions about NDEB which are not collectively predicted by any other theory of this phenomenon. OI achieves these results without having to make any special assumptions specific to NDEB. This places OT-CC at a considerable advantage as a theory of opacity relative to rule-based phonology, where NDEB requires stipulated restrictions on rule application like the Strict Cycle Condition (Kean 1974, Mascaró 1976). Chapter 5 shows that OI also lends itself to the two other main types of serial phonology/morphology interactions: \u27cyclic\u27 overapplication of a process, and underapplication of a process in a morphologically-derived environment. The chapter also critiques existing theories of these effects, particularly OO-faithfulness (Benua 1997), Stratal OT (Kiparsky 2000), and the phonological application of the theory of phases (Marvin 2002)