Double Plus is a unique series for skills development which consists of ten books and takes learners smoothly from Beginner to Proficiency (C2) level. It is based on a multi-dimensional syllabus and enables students to enhance their listening, speaking, reading and writing skills in an integrated way. Beginner to Proficiency A1, A2, B1, B2, C1, C2. Suitable for Cambridge, Michigan and other Exams