本稿針對指導「正式的語言」中的敬語要素「です」．「ます」之意義提出檢討。首先指出對於初次見面的人使用「非正式的言語」時所產生的問題點，接著論述包含於「正式的語言」內的「です」．「ます」。另外透過對學習者的授課，發現學習者即使經過一段時間的學習對「ます」的理解仍有不足之處，為避免此一現象乃提出一指導的試案。 最後並主張在指導待遇表現時「です」．「ます」的使用意義－「說話者應考量對方的立場及所處的場合，以及對對方表達敬意的意識指標」應該仔細指導。

In this article, I discuss what it means to teach the polite use of the language with the polite morphemes of "desu" and "masu" in Japanese. First, I deal with the problem of using "informal language" to people we meet for the first time, followed by the use of "desu" and "masu" contained in the "polite language." Also, I point out the fact that our students, even at a fairly advanced level of learning, lack sufficient undersanding of the importance of using "desu/masu" forms. As an attempt to solve this problem, I propose a tentative plan of teaching, followed by my suggestion as to the order in which these sentence-final styles are to be introduced in teaching. In conclusion, I make a point that, in teaching politeness expressions, it is crucially important for us to make all learners of Japanese realize once and for all the fact that the use of the polite morphemes of "desu" and "masu" contained in the polite language represents the underlying consciousness of the speaker to pay "respect" and be "polite" to the listener with full consideration of his or her position in society and the situation at the moment.