Abstract
SD-Forms are syntactically categorized as concept label, prescribed form, connected form, statement form and emotion form. Guidelines to SD-Form usage are described by showing examples. The SD-Form works as an interlingua of natural languages. It is also useful for knowledge description of a system. As an application, the authors built an English and Japanese conversational textbase having SD-Forms as meaning data. The source material was a series of conversational English study-textbooks for a radio program in Japan. The textbase was used in an English and Japanese conversational-text retrieval system.