2018 Volume 24 Issue 2 Pages 91-179
Harada (1971) argued some forty five years ago that the Japanese phenomenon called ``Nominative/Genitive Conversion'' (NGC) was undergoing a syntactic change, which was detected as idiolectal variations. Synchronically, Miyagawa (2011) argues that the NGC is not a free alternation but that more stative predicates are more likely to accept a Genitive subject. However, no one has ever proposed an argument that bridges the synchronic preference for ``stativity'' of the NGC and its diachronic syntactic change, which is characterized as ``stativization.'' In this article, we will show that the diachronic syntactic change has been in progress at least for the last 100 years. It will be shown that the semantic ``stativization'' is an epiphenomenon of the syntactic microparametric change which we refer to as ``clause shrinking,'' or a change in the syntactic size of the Genitive Subject Clause (GSC) from CP to TP to vP to VP/AP. Moreover, we will explain how such a drastic language change have actually influenced language acquisition for children who were born in different time periods, by integrating Kayne's (2000) microparametric syntax, Snyder's (2017) theory of competition between incompatible constructions, Lightfoot and Westergard's (2009) micro-cue analysis of language acquisition, Manzini and Wexler's (1987) Subset Principle, and Bošković (1997) Minimal Structure Principle.