Enter (published by Cornelsen). This is not your dusty, text-heavy grammar book from high school. It’s a colorful, exercise-driven, and communication-focused workbook that has become a secret weapon for learners across the globe.

Unlocking German Grammar: A Deep Dive into “Grammatik aktiv A1–B1”

Use the Cornelsen Lernapp (free with book code) to do the interactive versions of the exercises. The app gives instant feedback.