「ノダロウ」と「ラシイ」の異同について

Abstract

The present study explores the grammatical meaning of “presumptiveness” by specifically addressing nodarou-sentences and comparing them with rashii-sentences. To this end, we analyse such issues as the method of presumption, the type of presupposed sentences, and the way a presupposed sentence relates to a presumptive sentence. The main findings are summarised as follows. Firstly, nodarou-sentences enable both (i) inductive inferences which derive a general proposition based on concrete facts and (ii) deductive inferences which derive a concrete fact based on general propositions. By contrast, rashii-sentences allow inductive inferences alone. Secondly, presupposed rashii-sentences generally describe what a speaker directly experienced. Whilst the typical information source is auditory experiences, some rashii-S represent “hearsay information” and other rashii-S represent inferentially derived information. Further, the information source may be a visual or tactile one, and an inference may also be involved. On the other hand, presupposed nodarou-S are basically based on direct experiences, but it may be based on an indirect recognition in some cases, as can be confirmed by the forms such as rashii, kamoshirenai, and hazuda. Thirdly, a presupposed sentence is quite flexibly related to a presumptive sentence in the case of nodarou-S. That is to say, in the complex-sentence environments, they may be related to the matrix clause in terms of a causal relation or a conditional relation. Also, in the simple-sentence environments, they may be placed before or after a presumptive sentence, and they may be semantically connected. On the other hand, presupposed sentences which serve as a basis for rashii-sentences tend to be placed as simple sentences rather than complex sentences.