A proper treatment of syntax and semantics in machine translation is introduced and discussed from the empirical viewpoint. For EnglishJapanese machine translation, the syntax directed approach is effective where the Heuristic Parsing Model (HPM) and the Syntactic Role System play important roles. For Japanese-English translation, the semantics directed approach is powerful where the Conceptual Dependency Diagram (CDD) and the Augmented Case Marker System (which is a kind of Semantic Role System) play essential roles. Some examples of the difference between Japanese sentence structure and English sentence structure, which is vital to machine translation~ are also discussed together with.
