This document is the introduction from the teacher's edition of the English language textbook Postcards. It provides an overview of the course components and principles behind the course design. The course aims to engage teenage students by focusing on relevant topics and activities. It offers a variety of exercises to develop language skills while allowing students opportunities for self-evaluation and monitoring progress. The teacher's edition provides lesson notes and answer keys to support teaching the student book, workbook, and additional materials. Suggestions are also given for effective classroom management.