No consonant-final stems in Japanese verb morphology

Japanese has been conventionally considered to show two distinct distributional regularities holding in morpheme-final position: at the lexical level, verb stems can end with either a vowel or a consonant, whereas other morpheme types and derived/inflected forms must end with either a vowel or the placeless nasal n. Mono-stratal models of phonology call into question the validity of the traditional underlying-surface distinction, and respond by allowing only a single type of static pattern. Unlike the standard derivational approach, however, the mono-stratal approach cannot express the disparity between lexical and non-lexical patterns (Scobbie et al., 1996; Harris, 1997, 2004). This paper adopts a mono-stratal approach to investigate regularities in the pattern of morpheme/word-final segments in Japanese, and challenges the widespread view that Japanese employs consonant-final verb stems (e.g. jom ‘read’). Instead, it claims that the actual shape of apparently consonant-final stems is the same as that of non-past forms which end with ɯ (e.g. jomɯ), the neutral vowel of Japanese. This has the result of excluding consonant-final stems from the Japanese system — a system which prefers vowel-final forms. In terms of phonology-phonetics mapping, the stem-final ɯ is the phonetic manifestation of a melodically empty nucleus. This analysis has the benefit of allowing us to eliminate operations such as ɯ-deletion and vowel alternation. By positing a morphologically driven process which avoids empty positions at the morphological boundary, the empty position is simply filled by the initial vowel of the negative suffix (e.g. jo.m∅ [jomɯ] + -a.na.i → jo.ma.na.i [jomanai]).