This guide, designed for teachers of second languages to adults, discusses instruction for student groups of mixed abilities. The first chapter examines the factors that determine mixed ability, including: student motivation, interests, and needs; linguistic ability; general educational background; learning style; age; external pressures and time available to study; and anxiety. The teacher's need to differentiate between learners is also discussed. Chapter 2 describes strategies for getting to know the students: pre-course counseling; questionnaires; ice-breaking classroom activities; activities to help students know themselves; and record-keeping. The third chapter offers techniques for creating the right classroom atmosphere, developing students' study skills, involving learners, planning and organizing lessons, and starting on a small scale. Chapter 4 enumerates strategies for fostering learning: providing variety in the classroom; using a progression setting appropriate achievable goals; deciding whether to use different tasks for different ability levels; using role-play; supporting independent learning; dealing with ability differences in group oral work; group and pair work; and grouping. Appended materials include a sample 2-hour lesson plan, catering for mixed ability, notes on the responsibilities that devolve to administration, and a brief discussion of accreditation. Contains fourteen citations for further reading.