Nominative Case-Marker Omission and A-Chain Deficit in Child Language Acquisition of Korean

The present study investigates the account of the A-Chain Deficit Hypothesis (ACDH) on the omission of the NOM(inative) case marker in child Korean, which argues that children omit NOM frequently in unaccusative constructions due to the unavailability of A-movement.1 Overall, the results of this study confirm previous results on the rate of NOM omission used to support the ACDH (Borer and Wexler 1987, Miyamoto et al. 1999, Lee and Wexler 2001, Machida et al. 2004). Previous studies used a bi.nary distinction between verb categories, i.e., unaccusatives vs. the others (unergatives/transitives). Once the various subclasses of unaccusatives are considered individually (adjectival, copular, existen.tial, psych, and lexical unaccusative verbs), the unaccusativity effect is found not to hold across all un.accusative verb types. The results of detailed analyses appear not to support the ACDH in that not all verb subcategories follow the pattern among verb types suggested by the simple binary categorization