A fully-revised edition of the best-selling course that teachers trust and students love. Each level is 90-120 hours and consists of 20 core units with a review section after every two units. The interleaved Teacher's Book gives lots of support with excellent lesson notes and ideas for extra activities. Placement tests help teachers decide which level is right for their students and a Test Book with tests for each level helps monitor students' progress. Especially for Swiss students, there is a multi-lingual wordlist.