When it comes to learning grammar, the best way is to just do it!
For learning grammar, you'll find the most success in retaining
your skills through drills, drills, and more drills. Following the
formula of the bestselling "Verb Drills" series,
"German Grammar Drills" will reinforce your knowledge and
enhance your ability to read, write, and speak in German. This book
introduces essential grammar concepts, with practical examples to
demonstrate their correct usage.
No other language book focuses so exclusively on practical
exercises
The Verb Drills series has sold more than 300,000 copies
Ed Swick taught German for thirty years. He is the author of several books on German and ESL such as Practice Makes Perfect: German Pronouns and Prepositions and German Conversation Demystified.