I just bought this book and read 5 pages so far. And I love it! I can speak English, my second language, very well. But I want my vocabulary to be as good as a native speaker, so I was looking for a book that only includes high-level vocabulary and shows how to use them in phrases. This book is the answer and more! It groups words by their roots, and gives a little story of the roots at the right level. Under each root, there are usually 3 or 4 words, which I think is a good quantity. I found this effective in learning similar words quickly. Each word is followed by abundant yet short phrases to illustrate its meanings and connotations. The phrases are informative and fun to read. After several roots, you can take quizzes to see how much you have learnt or forgotten. I highly recommend this book to anyone who wants to build a powerful vocabulary in an effective way.