Morphophonological variability and form-function regularity: a usage-based approach to the Japanese modal adverb yahari/yappari/yappa

Based on corpora and survey studies in the framework of a usage-based model, this paper claims that morphophonological variations of the Japanese adverb (yahari, yappari, yappa) are not “free” variations, as treated previously. Positionally, yahari is predominant in utterance-internal positions, while yappari and yappa appear utterance-initially/finally. Functionally, yahari is a sentential adverb ('as expected/after all'), while yappari and yappa show emerging pragmatic functions (e.g., filler). Semantically, (inter)subjectivity increases from yahari to yappari then to yappa. This paper argues that such differences are correlated with phonological shapes (e.g., the mora obstruent /Q/), and are motivated by the principles of iconicity.