How variational acquisition drives syntactic change: The loss of verb movement in Scandinavian

Although language acquisition is frequently invoked as a cause of syntactic change, there has been relatively little work applying a formal model of acquisition to an actual case of language change and testing its predictions empirically. Here we test the model of Yang (2000) on the historical case of the loss of verb movement to Tense (V-to-T) in Faroese and Mainland Scandinavian, using quantitative data from a number of corpora. We show that the model straightforwardly predicts the historical data, given minimal and uncontroversial assumptions about Scandinavian syntax. In contrast to a number of previous attempts to explain this repeated pattern of change, it is not necessary to appeal to any bias against learning structures involving V-to-T—a welcome result, given current evidence from acquisition. The newer V-in-situ parameter setting overcomes the original V-to-T grammar because it is more learnable in a language that also has embedded verb-second (EV2). Finally, we argue that the course of the diachronic change is evidence against a strong version of the "Rich Agreement Hypothesis" (RAH), but that under this account the stability of V-to-T in Icelandic provides evidence for the weaker version (cf. Bobaljik 2002).