A Study of the Essential Nature Common to Various Core Types of Japanese Topic

This study aims to search for the deep underlying essence of the Japanese topic marker wa digging up a common trait among several core types of 'topicalized sentence's (this study will hereafter use this term for convenience sake referring to the sentence with a topicalized word marked by wa) with wa-marked topic each of which has hitherto been considered especially by Noda (1996) to have its own essential property of wa, and to define the single universal nature of wa finding out what it has been that wa shows as wide-ranging phenomena. It seems to the author that wa is not a case particle proxy but a superordinate deeper-lying word that might be more than we can grammatically handle in a regular way within the rectilinear structure of a sentence presented on paper. This study, therefore, seeks to define, especially according to Tanimori (2021), what it is that could be expressed with the simplest way in the sense that seeming endless definitions of wa depending on various types of outward phenomena produced in wa-sentences should ultimately be led to converge into one simple formula for wa, i.e., the essential nature of wa.