As a German learner, I consider verbs one of the most problematic aspect besides grammar. More precisely, it's extremely difficult for low-level learners to conjugate verbs and to distinguish verbs with the same root and different prefixes. This book resolves that problem quite well. For each verb, on the left hand page, you will find the detailed conjugation whereas on the right hand side, it shows the examples together with other verbs built by combining the base with different prefixes. The only thing I don't like so far is that the book was written in German only, so you may need to reach a certain level of German to read the instructions (I still have difficulties even at B1 level).