Instructor Certification Course - Defense Language Institute Foreign Language Center - 2023120 hours of the Instructor Certification Course. Able to provide individual lessons for Defense Language Proficiency Test (DLPT) and Oral Proficiency Interview (OPI) preparation, supporting students ahead of their exams. Able to teach listening, reading, writing, and speaking skills, as well as geopolitical, economic and social issues, in an immersion-based environment.