This textbook is written exclusively with the aim of improving the English proficiency, technical skills, and professional competence of prospective UT School instructors. The instructional materials in this book are comprehensively organized with an emphasis on three important aspects, namely: (1) theory and application of functional language in formal and informal contexts, (2) reading and understanding operation and maintenance manual, and (3) professional competence of an instructor, particularly in planning, implementing, assessing and evaluating the training process.