Abstract
The purpose of this study is to point out why the intermediate-advanced learners sometime produce unnatural Japanese sentences; such as "ashita kenkyuushitsuni mairu to sensei ni otsutaekudasai." The results show that the activities to get the skill of distinguishing the differences between the usages of the humble word MAIRU, UKAGAU and the usages of polite word MAIRU are provided in the intermediate-advanced class.
