In a special Focus-to-Predicate concord construction (kakari musubi), specific focus particles called kakari joshi correlate with predicate conjugational endings, or musubi, other than regular finite forms, creating special illocutionary effects, such as emphatic assertion or question. In Old Japanese, a particle ka, s(/z)ö, ya, or namu triggers an adnominal ending, while kösö calls for a realis ending. In Old Okinawan, ga or du prompts an adnominal ending, while sɨ associates with realis endings. Kakari musubi existed in Proto-Japonic but died out in the Japanese branch; however, it is still preserved in its sister branch, Ryukyuan, in the Okinawan language.
This concord phenomenon, observed in only a few languages of the world, presents diverse issues concerning its evolution from origin to demise, the functional and semantic differences of its kakari particles (e.g., question-forming Old Japanese ka vs. ya) and positional (sentence-medial vs. sentence-final) contrast. Furthermore, kakari musubi bears relevance to syntactic constructions such as clefts and nominalizations. Finally, some kakari particles stemming from demonstratives offer worthy data for theory construction in grammaticalization or iconicity. Because of its far reaching relevance, the construction has garnered attention from both formal and functional schools of linguistics.
