This paper aims to explain a euphonic change, so-called I-onbin, on Japanese verb conjugation within the framework of Emergent Grammar.
There have been arguments over underlying representations on Japanese verb conjugation in the previous studies. Archangeli & Pulleyblank (2017) proposed a model of Emergent Phonology, which was built in surface-oriented morph model without underlying representation. I adopt this model in this paper, and explain the euphonic change, I-onbin without any underlying forms. Therefore, in this study, we can be free from arguments about underlying representations on Japanese verb conjugation.
It was a difficult problem to explain the opacity of I-onbin on Japanese verb conjugation in Classic Optimality Theory (Prince & Smolensky 1993/2002). Because Optimality Theory is based on parallelism without derivation. The Emergent Phonology model is also based on parallelism, but opacity is not an issue in this model. Because opacity is a problem that occurs on the premise of a single underlying representation for each morpheme, but the Emergent Phonology model does not assume underlying representation. This paper shows that the opacity of I-onbin on Japanese verb conjugation, which was difficult to handle in Classic Optimality Theory, is not an issue in Emergent Grammar.