The C-Grammar presents German grammar at the highest level of the Common European Framework of Reference for Languages (C1 and C2). It provides an overview and demonstrates the structures in their complexity and depth with many additional examples and stylistic variations. For each grammar topic, there are numerous exercises in various forms and difficulty levels to apply what has been learned. Exercises with lower difficulty levels serve to clarify, repeat, and reinforce the structures. High-difficulty exercises primarily include transformations of sentences and texts. Their function is to train the flexible use of different grammatical structures, to sensitize the language feeling, and to convey stylistic confidence. Learners can choose exercises based on their own needs and learning goals. The exercises are embedded in communicative and authentic contexts. A didactic section in the appendix offers suggestions for educators on creatively dealing with grammar. Additionally, the appendix contains overviews of spelling and punctuation, verbs, adjectives, noun-verb connections, as well as prepositions and sentence connections in adverbial phrases. The C-Grammar is suitable as supplementary material for courses, for individual study, or as a reference grammar for educators. The C-Grammar now also offers an option for the additional purchase of the corresponding e-book license.