In support of an OT-DM model: Evidence from clitic distribution in Degema serial verb constructions

This paper provides support for a modified DM model which I call Optimality-Theoretic Distributed Morphology (OT-DM). The strongest form of this model is that all morphological operations take place in parallel, which I call the Morphology in Parallel Hypothesis (MPH). Although combining OT and DM is unorthodox in practice, I show that a growing body of data warrants this modification (Trommer 2001a, 2001b, 2002; Dawson 2017; Foley 2017; a.o.). I provide support for OT-DM from the distribution of verbal clitics in Degema, a language of southern Nigeria. Within, I argue that agreement clitics are inserted post-syntactically via the DM operation Dissociated Node Insertion (DNI), and further that verb complexes are formed post-syntactically via the operation Local Dislocation (LD), operating in tandem with a well-formedness markedness constraint which requires verbs to appear in properly inflected words. These DM operations are decomposed into a series of constraints which are crucially ranked. Candidates are freely generated from gen and are subject to all DM operations, and are evaluated via eval against the ranked constraint set. I illustrate that under the standard serial DM model in which DNI proceeds VI, this would result in the wrong output form, and that even after parameterizing DM operation order in response, this model does not adequately capture the motivations behind the morphological patterns.