Formal mismatches and functional advantage in syntactic change

This paper relies on the idea that syntactic change stems from linguistic factors that are different in nature and, consequently, trigger different results. Specifically, I distinguish the causes, processes and results related to two different kinds of syntactic change, a ‘formal’ type of change vs. a ‘functional’ one. The hypotheses pursued here are the following: (i) Mismatches between the formal features a learner has acquired and certain data she receives during the language acquisition period lead to a syntactic change type, which restructures completely the syntactic derivation involved; (ii) The advantage of parsing one variant over parsing another triggers a different kind of change, namely one that affects specific instances or uses / registers of the crucial syntactic structure. To illustrate this, I analyze the role of functional advantage and formal changes in the historical development of the case system of Russian non-verbal predication.