Towards optimal rhythm [electronic resource]
Keywords: Linguistics.

This thesis argues that rhythmic well-formedness preferences contribute to conditioning morphosyntactic choices, providing evidence from patterns in language use that constraints on phonological constructs are at work in the assessment of competing morphosyntactic variants. The results of the thesis call into question a fundamental empirical assumption underlying many standard models of grammar and of language production: that metrical or segmental phonology cannot influence morphosyntactic encoding. Phonologically-conditioned morphological phenomena are of familiar stock. Phonological constraints can force blocking of morphological processes and combinatorics, resulting in a number of repair strategies: re-ordering, periphrasis, deletion, and suppletion. It is shown in this thesis that phonologically-conditioned syntactic phenomena follow a similar typological spread. The same phonological constraints that interfere with morphology also operate across word and phrase boundaries, triggering repairs of word (re-)ordering, periphrasis/paraphrasing, deletion, and suppletion (i.e., lexeme replacement). Two empirical studies of the rhythmic conditioning of word choice (e.g., personal name choice) and syntactic choice (e.g., genitive alternation) in English are presented. The case studies demonstrate that rhythmic optimization, in addition to other phonological well-formedness preferences such as phonotactic co-occurrence restrictions, are active in word and construction variation in syntagmatic contexts. It is furthermore shown that the effect of rhythm is closely tied to semantic factors such as animacy, which reveals that rhythm must interact and compete with non-phonological constraints in the system. Allowing interaction between phonological material and morphosyntactic choices raises the issue of how much surface and underlying phonetic and phonological information is available at the point of morphosyntactic computation. Rhythm offers a natural test case of the availability of underlying versus post-lexically specified information via the distinction in stress properties of lexical (content) and grammatical (function) words. A large-scale corpus study of content and function word stress in conversational American English is presented. Results of the study point to complex differences between word categories in terms of underlying and surface stress properties. These differences in stress not only trigger differences in rhythmic optimization by word category but they also demonstrate that morphosyntactic competitors are assessed without consideration of the potential output of surface rhythmic optimization. In contrast, evidence from end weight phenomena suggests that lexically-encoded information about underlying phonological stress is available during morphosyntactic computation. The view that emerges from the empirical studies in this thesis is one that allows for potential phonological influence on morphological and syntactic outputs. The phonological constraints that are most active will necessarily be ones that regulate syntagmatic effects that occur when words combine in the morphosyntax, and these phonological constraints—including the propensity towards optimal rhythm—must compete for satisfaction against other active, non-phonological pressures.