Trubetzkoy (1958/69) proposed that natural languages fall into two groups, mora-counting and syllable-counting languages, according to the smallest prosodic unit used in that language. Japanese has been classified as a mora language, whereas English is labeled a syllable language. This proposal has been taken for granted over the decades and has been interpreted as suggesting that the mora and the syllable are mutually exclusive within a single prosodic system. This paper challenges this interpretation by demonstrating that at least one major role which the mora plays in Japanese is observed in syllable-based languages as well and, moreover, that the syllable plays a pivotal role in a wide range of linguistic phenomena in the putatively mora-based system of (Tokyo) Japanese.
