I view the study of suprasegmental phonology as essential to understanding what is possible at the boundaries between phonology and morphosyntax, and, in particular, how the domains of phonological processes are construed, whether prosodic and/or morphological. By virtue of their long-distance nature, suprasegmental phenomena allow for a unique look at the interface with morphosyntax. In my work, I have looked at suprasegmental phenomena including nasalization, tone and harmony. I'm particularly interested in what suprasegmental phenomena can tell us about the division of labor between phonology and morphology.
Nasalization
In my dissertation, I examine three distinct places in the grammar of Atchan which show morpheme-specific nasalization patterns: auxiliaries, serial verb constructions, and reduplication. I argue that the attested differences in surface phonological output in Atchan are tied to differences in underlying morphosyntactic structure: nasalization from singular subject pronouns represents the exponence of subject features, expressed on every verbal head within a particular morphosyntactic domain. I connect my analysis of the morphosyntax-phonology interface in Atchan to larger theoretical questions about possible domains of phonological processes, proposing a historical pathway from automatic processes driven by coarticulation, which are delimited by phonological constituents, to phonologized processes which have morphosyntactic constituents as their domains.
Tone
In my work on Kru languages, I have looked on the phonology and morphosyntax of negation, which is expressed by the addition of a High tone to the right edge of the material in subject position. I find that tonal subject marking of negation developed over time from the phonological erosion of a negative marker *ní. In certain environments, which are slightly different in different languages, the negative marker has a solely tonal allomorph. I argue that this suppletive allomorphy is triggered by the features of the subject. I also note that, in languages of West Africa, it is quite common for inflectional material like auxiliaries to display patterns of suppletive allomorphy of this type, in which one allomorph has both tonal and segmental content and one allomorph is purely tonal. I suggest that, diachronically, this kind of suppletive allomorphy is a common source for the formation of STAMP morphs, in which inflectional morphological information is expressed on the subject of a clause. As the diachrony of African tonal languages remains understudied, particularly at the macro level comparing across languages, this work is an important contribution to our understanding of how morphological marking may shift over time.
Harmony
Informed by initial primary data collection with two native speakers of Paraguayan Guaraní, I conducted a corpus study of sociolinguistic interviews in order to investigate factors which influence the actual application rate of nasal harmony. I found that several factors significantly affect application rate, including one morphosyntactic factor in particular: proclitics harmonize at a significantly lower rate than prefixes, despite the two types of morphemes competing for the same slot in the morphology. This demonstrates that morphosyntax can be a significant factor conditioning variation in harmony. I am also interested in the diachronic development of nasal harmony in the larger Tupian family. In a joint project with Myriam Lapierre (University of Washington), we find that all languages of the family can be categorized into one of four types of nasal harmony, classified in terms of the directions of [+nasal] and [-nasal] spreading. We put forth a proposal for how these distinct systems may have emerged over time, modeled through different rankings of the same constraints. Crucially, all languages obey the same high-ranked constraint: adjacent segment edges must match in their value for [+/-nasal]. The actual surface outcome for each harmony system is determined by the relative weighting or ranking of relevant faithfulness and markedness constraints. In this work, we take a look at the interface between phonetics and phonology, showing that the emergence of nasal harmony in these languages comes from the imperative for segment edges to match.