Non-monotonic functional sequences: A new metric for complexity in heritage languages

Abstract

This paper presents some evidence that language change in heritage languages (and beyond) systematically responds to general factors of language design when it comes to fixed sequences of functional heads within given domains. Concretely, we investigate patterns of change across various heritage languages, both in the wordinternal domain (person and number features) and at the sentence level (word order): we show that change in these different domains is consistently shaped by a bias towards monotonicity and uniformity in computation, such that points of nonuniformity in the relevant sequence can be predicted to be the gateway to change. Crucially, this change systematically brings about a reduction in complexity; as such, these factors are proposed as a new metric for linguistic complexity