Intended as a practical aid for teachers, the fourth edition Teacher's Guide provides a wide range of resources for teachers -- from notes on the content of a unit and how to approach the exercises, to suggestions for classroom activities and answers for all the exercises in the Student Book. The fourth edition Teacher's Guide has been greatly expanded to include such features as: Thematic PowerPoint lessons to provide reading-based review of grammar structures. Step-by-step instruction for exercises and all of the charts. Background Notes Boxes with suggestions and pedagogical notes to assist with lesson planning. Expansion Activities that promote independent, active use of the target structure. Optional Vocabulary for many of the exercises. A comprehensive Student Book answer key.