Language Acquisition in German and Phrase Structure Change in Yiddish

There is a long tradition stretching back into the 19th century of implicitly assuming a relationship between language change and child language acquisition in the notion of “reanalysis”1. Recently, studies such as Yang (2000) have developed formal models of language acquisition and expanded them to model how new syntactic variants can arise among children and be maintained in adult speech communities, formalizing the notion of “grammar competition” Kroch (1989). However, there have been very few empirical studies of language acquisition that can be linked to specific, well-documented cases of grammatical change. This paper investigates the relationship between acquisition and change in a study of a major phrase structure change in the history of Yiddish, the change in the structure of TP from a German-like Tense-final grammar to its modern Tense-medial grammar (Santorini 1992, 1993). In particular, this study will ask: was the direction of this change predetermined? Additionally, this paper explores the question of exactly what parameter was changing when the position of the tensed verb changed in the history of Yiddish, and I will suggest that an antisymmetric approach to headfinality allows for a more precise understanding of how this historical change took place.