Types of Case Alternation in the Japanese ‘Ga’ Case Object Construction : The Types where Alternation Occurs on either the Subject or Object

This paper focuses on the types of case alternation in ‘Ga’ case object constructions and examines the types where only one of the subject or object case markers is replaced. To investigate this, we presuppose that ‘Ga’ case object constructions are unaccusative constructions and explain case alternation in relation to the subject's controllability over the matter expressed by the predicate. While the subject is fundamentally not an agent who can control the matter expressed by the predicate in ‘Ga’ case object constructions, the ‘Ni’ case subject demonstrates an even stronger [– controllability] compared to the ‘Ga’ case subject. In contrast, even in ‘Ga’ case object constructions, if the subject is considered to have some degree of [+controllability], it can take an ‘O’ case object. Predicates where only the subject is replaced with the ‘Ni’ case typically express matters such as existence/absence, possibility/difficulty, necessity/importance, and emotion. For these predicates, the subject’s controllability is not recognized, and the subject is regarded as having a more passive semantic role. Predicates where only the object is replaced with the ‘O’ case mainly express emotions such as preference, hope, or desire. This suggests that these emotions are perceived as more controllable compared to other emotions.