I have been studying English

A friend recommended me a book named <English Grammar in Use>. Then I bought the intermediate version of it (is that what you meant with medium?). There isn't any Chinese in the book, but I can understand it. I have many Chinese version of grammar books, and those books were my textbooks when I was in junior high. It is strange that I can't understand very well the Chinese version of the grammar book , but I fully understand the English version of it. When I have a chance, I do some exercises. I really like this book. And thanks to my friend in Hong Kong.

-revised version-

A friend recommended me a book named "English Grammar in Use". Then I bought a medium. There isn't any Chinese characters in the book but I can understand it. I have many Chinese version of grammar books and those were my textbooks when I was in Junior High. It is strange that I can't understand the grammar book with chinese well, but I can understand the English version of it very well. When I have time, I do some exercise. I really like this book. Thanks to my friend in Hong Kong.

~ I spot only minor errors. Your doing a great job :)