Contrasting languages or their subsystems is an activity, the results of
which not only enhance our knowledge of the structures of languages, but also contribute to such fields as translation and language teaching. Languages like all things in nature are similar in some aspects and different in others, but when we compare languages we are more concerned with similarities and when we contrast them we are interested in their differences. The basic claim of applied contrastive analysis is that students - of foreign languages make certain systematic errors in the process of learning that can be attributed to the interference of the patterns and structures of their mother tongue or their first language. Therefore, we are justified to compare and contrast languages to account for some of the deviant structures produced by students. The present research attempts at contrasting some aspects of one subsystem of Persian and Japanese, namely, their phonological structure.
Persian and Japanese belong to different language families, but as we shall see their phonological systems are similar in some respects though there are differences.