In recent years various applications are routinely used by the spread of computers.The difficulty in operating those applications have been increasing as the functions of applications get complex. If we can operate those applications with words, complex operation procedures could be performed with simple natural language commands. This would lead to expand the possibility of operating applications by people who are not used to using applications. In this study we therefore propose a method to flexibly connect the commands of various kinds of applications with natural language commands. We do semantic analysis with semantic case. As an example of our proposed method, we build a natural language interface to operate Google Calendar.