Abstract
In this study, I investigate the evolution of directive expressions, in particular, the usage of the imperative form of honorifics and benefactive verbs. Directive expressions are classified into four types: command, command that benefits the hearer, request, and advice. These types are classified under benefit (speaker or hearer) and authority (speaker or hearer). In Middle Japanese (around 1600), benefactive verbs were only used as requests. However, in Early Modern Japanese (1610-1868: Edo period), these verbs were also used as advice, and in Modern Japanese (1868-1926: Meiji period- Taisho period), they were used as all the four abovementioned types of directive expressions. Honorifics, on the other hand, were used as all the types in Middle Japanese, but in Early Modern Japanese, they were not used as requests. In present-day Japanese (Showa period-), they cannot be used as advice. In other words, honorifics cannot be used to hearers who have priority as directive expressions. This change has been brought about by the formation of the pragmatic rule that the speaker must show the benefit to himself by using benefactive verbs. This pragmatic rule was in practice until Modern Japanese. As a result, benefactive verbs have become polite directive expressions in present-day Japanese, and honorifics, which do not show benefit, cannot be used with a superior.
