[Development of Temporal Systems in Child Language from the Viewpoint of Universality and Variation in the Encoding of Time in Human Languages].

This study explores how time is conceptualized and linguistically encoded by human beings. In order to examine how the temporal systems develop in child language, we have conducted investigations on how their development relates to universal and idiosyncratic aspects of the temporal systems of the languages of the world. We have found that both the uniformity and the variation across languages in the development of tense-aspect marking in child language are attributable to the interaction of three aspects of the typological pattern of the target language: morphology, the presence or absence of optionality of tense-aspect marking, and the inventory of tense-aspect markers.