Relative frequency and the holistic processing of morphology

This study presents apparent-time changes in the morphology of the expression mitai-na ‘similar to’. Based on apparent-time data, we argue that the morphological boundary between mitai and the attributive morpheme -na in the phrase mitai-na has disappeared, and that this complex phrase is now processed as a monomorphemic form. We suggest that relative frequency is the key to understanding the results.

We further supplement our argument with data on the standardization of the adverbial adjective form in the Kansai dialect. Young speakers overwhelmingly use the standard form of adverbials for all adjectives except two: yō ‘a lot, well’ and hayō ‘quickly, early’ (instead of Standard Japanese yoku and hayaku). The three linguistic forms that display unusual behavior (mitai-na and the adverbial forms of yō and hayō) all have a high relative frequency. We conclude that when a complex form occurs more frequently than its components (high relative frequency), then it behaves as a monomorphemic unit. The irregular adverbial forms are leftover from an obsolete system, in the same way that many English irregular past forms are leftover from the Germanic strong verb system. In contrast, the irregular form mitai-na emerged from and competes with the regular inflection paradigm for mitai, illustrating a previously undocumented path for the diachronic emergence of irregular morphology.