Tohono O'odham syllable weight: Descriptive, theoretical and applied aspects

Abstract

This dissertation is a model of a unified study of three linguistic aspects: description, theory and application. Tohono O'odham syllable weight is investigated within these linguistic aspects. I propose that O'odham diphthongs are categorized into two groups based on their weight: light (monomoraic) diphthongs and heavy (bimoraic) diphthongs. This is opposed to generally understood diphthong classifications (i.e., falling vs. rising). My conclusion is supported by empirical facts, including morpho-phonological and phonetic phenomena. The generalization is theoretically accounted for within the framework of Optimality Theory (McCarthy and Price 1993, Prince and Smolensky 1993). Moraicity of the light/heavy diphthongs and short/long vowels are analogous, and the larger classification of Tohono O'odham vowels is made: Class L (monomoraic vowels) and Class H (bimoraic vowels). However, the distribution of the vowels depends on syllable type: stressed, unstressed and irregularly stressed. This dependency is accounted for by the following: (i) Predictable moraic structure is not specified in input (this is explained with a proposed constraint, MORAINDISPENSABLILITY or MI); (ii) Moraic specification is in the input only where it must be lexically specified (long vowels and irregularly stressed diphthongs); (iii) Light diphthongs surface as monomoraic due to the loss of a mora. In order to account for the relationship between the unstressed position and light diphthongs, I propose a constraint, POSITIONALDIET, a relative of the Stress-to-Weight Principle or SWP (Prince 1990). Evidence for the diphthong classification comes from an acoustic study of a native speaker and learners of Tohono O'odham. In addition to supporting the classification, the differences between English and Tohono O'odham speakers' treatment of diphthongs is explained with respect to the fact that English diphthongs are always heavy. Finally, implications of this study for Tohono O'odham language teaching are discussed.