On postposition in present-day Japanese

Postposition in Japanese has been regarded as a part of speech, corresponding to Preposition in Indo-European. However, no satisfactory answers have been given to the questions: (1) what is Postposition, (2) which should be called Postposition: Case particles: N (Noun) -ga, N-o, N-ni, N-e, N-to, N-yori, N-kara, N-made and N-de forms or the compound forms from a Case particle and an auxillialy word: N-ni tsuite, N-ni yotte, N-ni kanshite forms and so on, and (3) what is its system as Semantic category, expressed by the noun phrase with Postposition. The purpose of this paper, then, is to provide a satisfactory answer to these problems. Postposition is the system of the forms, having Noun to play semantic roles to the predicate in a sentence and different from Case, having the noun to play grammatical relations to the predicate. So, we admit both Case particles with Semantic roles and the compound forms from a Case particle and an auxillialy word with Semantic roles to Postposition. Namely Postposition consists of 2 forms level: [1] the primary form, which it is difficult to relate to any parts of speech; [2] the secondary form, which is undoubtedly derived from some other parts of speech: verb, noun etc. [1] expresses the fundamental notions and [2] expresses subdivided Semantic roles. Thus each of them fills in the blank of system of Semantic roles in Japanese