Business case studies, descriptions of management problems or decisions that require students to analyze and decide on an appropriate course of action, are suitable for classroom study of commercial language because the technique emphasizes situational analysis and communicative activities such as role playing. The principles underlying the case study approach are the following: (1) situational analysis encourages students to focus on specific real situations; (2) the relationship between analysis and action is demonstrated; (3) a learner-centered classroom is fostered; amd (4) students can develop an administrative point of view and the ability to size up a situation, consider a variety of approaches to solving it, and decide on appropriate action. On the teacher's part, the case study approach requires skill in leading a case discussion, understanding of the basic theory and concepts in the case, and language proficiency. The teacher must also give up some control of the class to promote open-ended discussion. Elements that the teacher can control are direction of the discussion, introduction of neglected information or options, and requests for clarification and summary. An appendix lists sources for case study materials in Spanish, French, German, and English, including the Harvard Business School Case Directory. It is noted that the Harvard Business School has devoted several cases specifically to teacher training. (MSE)