Some free sites may have typos or incorrect grammatical analyses.
Since it's a 2018 edition, it is widely digitized. You can find it easily on mobile-friendly sites, which is helpful for quick checking in class. Pros and Cons
Helps students understand where they made mistakes in complex syntax or spelling.
Instead of just copying, use the GDZ to . If your answer differs, look at the rule provided in the textbook and try to understand why the GDZ choice was made.