I am very impressed with the Pimsleur language lessons. The format for listening and repeating at 30 minutes a day makes it easy to learn both grammar and vocabulary. Purchasing the lessons from Audible makes these lessons affordable as compared to purchaing anywhere else. I started by doing Lesson 1 on the first day as advised. Then I did Lesson 1 and 2 the second day and then Lessons 1,2, and 3 the third day and so on until I was convinced that I has a lesson totally learned and then I would stop doing it. If a missed a few days I would go back several lessons and do them all.