Abstract
Background Based on signs prohibiting certain actions, people warn others using imperative forms of verbs or give a soft warning using politeness strategies. This study clarified how native Japanese speakers and Uzbek Japanese learners perform warnings based on prohibited signs. Methods After clarifying the difference between prohibition and warning, we proposed a classification scheme for the latter speech act in terms of politeness. Data were elicited using a discourse completion task. We prepared tasks for how participants verbally warn people who are about to perform prohibited acts in museums and hospitals, based on the prohibited signs. Results Native Japanese speakers tended to mitigate warnings by using two politeness strategies. The first politeness strategy was the use of rule-based expressions such as “It is forbidden.” However, such expressions may make the hearer feel that the speaker is an overbearing person who wields authority. To avoid this risk, Japanese speakers used the second politeness strategy of hedging inference, as in “Looks like it is forbidden.” They made it clear that the power to forbid does not rest with them, but with the public authorities, and furthermore, that it is only a possibility of their own speculation. The Uzbek learners of Japanese, on the other hand, were more direct in their warnings than the Japanese, and implemented a politeness strategy of apology as compensation. In some cases, the Japanese group and the Uzbek Japanese learners’ group did not warn. They did not warn strangers. Conclusions The characteristics of Uzbek learners of Japanese were found to follow the general characteristics of the learners’ language. This study presented a framework for classifying warnings about prohibited acts. This framework is applicable to languages other than Japanese, Uzbek, and Japanese spoken by Uzbek learners of Japanese.