Japanese and Vietnamese belong to two different language types. Japanese is an agglutinative language, while Vietnamese is an isolating language. This difference, along with the significant disparities in word order between Japanese and Vietnamese, makes learning each other’s languages challenging for both Japanese and Vietnamese speakers. The differing word orders in the two languages limit learners’ ability to speak fluently and write proficiently in the foreign language. A typical example is the difficulty learners face when encountering the structure of modifying clauses in Japanese. Therefore, teachers need to provide guidance in a way that makes this structure easier for learners to understand.