This book isn't for beginners; it's for intermediate learners who have already grasped some grammar and have developed various questions. It's easier to read than a textbook, with several fictional characters asking a teacher about Chinese grammar. Some people say the explanation of "了" is easy to understand. The summary in the final grammar section was also helpful. I didn't write in it, and from a quick look, there's nothing written in it. The exterior shows signs of aging, but the inside is clean.