Historical change in the Japanese tense-aspect system

Modern Japanese has a formally very simple tense-aspect system, which at its core has only three forms that are complemented by a number of peripheral markers and constructions. The core of the tense-aspect system was much more elaborate and complex in Classical Japanese. This paper discusses the systems of Modern and Classical Japanese, and then sketches the development from the latter to the former. This development involves the grammaticalization from aspect to tense, the recruitment of lexical means and constructions to renew aspectual categories, and category climbing. Two major paths of grammaticalization can be distinguished.