Instruct: Classify Amazon reviews into positive or negative sentiment
Query: "How not to learn Japanese"

I have seen many people study using this book. I think the name alone must sell a lot. I've never seen anyone gain real proficiency, though. If your goal is to gain a logical understanding of the grammar and some vocabulary while avoiding fluency, then this is the book for you.The problem is that the book presents itself as a method to gain fluency, but it is very light on exercises. In order to gain fluency, you must practice fluency. Building vocab, reading dialogues, and reading essays on grammar will never get you there.I highly recommend that people serious about gaining fluency supplement this book with something that is more exercise intensive. Or better yet, buy something else.