Morphological innovation and relative rates of change: a view from Amazonia

This talk considers the common assumption that grammatical morphology is likely to preserve more signal of language relationship than is basic vocabulary, and evaluates ways in which the dynamics and mechanisms of language change may make crucial reference to spatially and temporally variable aspects of typological structure and sociolinguistic practice. Through the lens of the Naduhup language family, further informed by a comparative look at three other Amazonian families, I present evidence for processes of morphological change that appear cross-linguistically unusual or extreme. These relate in particular to the rapid generation of new grammatical forms, even while basic vocabulary remains relatively conservative. These diachronic processes are plausibly facilitated by areally relevant structural characteristics that facilitate grammaticalization, including the prevalence of verb serialization and noun incorporation. They are also fostered by regionally salient sociolinguistic practices, particularly those associated with intensive, stable multilingualism, which promote contact-driven grammatical restructuring alongside language maintenance and constrained lexical replacement. This investigation highlights the fact that morphological and lexical domains may be subject to diverse rates and processes of change, particularly involving elaboration vs. replacement, and that these in turn may be sensitive to particular typological and sociolinguistic patterns.