Tense and aspect systems of Western and Eastern dialects in Japan
Previous research on the universal directionality of the development of aspect markers classifies them into two categories (imperfective vs. perfective), claiming that each group takes a distinctive path of semantic shifts determined by the meanings of lexical items from which the aspect markers are derived. However, this binary classification cannot account for the grammaticalization in the eastern dialects of Japanese. Furthermore, the western Japanese dialects have recently developed a distinction between the simple present and the present imperfective, although previous research claims that language generally tends to show simpler aspectual marking in the present tense, the imperfective being indistinguishable from the present tense. In this paper, I analyze corpus data from the 8th to the 17th century Japanese, which show that four periphrastic expressions, -<i>te wir-</i>, -<i>wir-</i>, -<i>te wor-</i>, and -<i>wor-</i>, all indicated aspectual meanings at some point in history, although they underwent separate paths of development in the east and the west of Japan. I claim that the separation of perfect and progressive marking seen in the west of Japan gives rise to the possibility of further semantic changes, whereas the semantic complexity of the aspect marker in the eastern dialects prevents any similar type of semantic shift.