NATURAL LANGUAGE INTERACTIVE DEVICE

PURPOSE:To form an interactive sentence using a proper honorific expression based on respective social relation by storing a belonging relation to the remote side of an interaction and a person appearing in the interaction and storing information for using an expression from these relations. CONSTITUTION:At the time of forming the sentence, an expression decision device 4 extracts a group to which the device itself and the remote side of the interaction belong from an subject belonging storage device 5, extracts a group to which the person appearing in the sentence belongs from a general belonging storage device 6, further extracts a honorific expression and a polite representation to be used to the person having the assignment relation from an expression storage device 7 and forms a natural language sentence based on the expression. Thereby, the natural language sentence using the proper honorific expression and the polite expression can be formed to the remote side of the interaction and the appearing person.