Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Quite good, but could be better

I grew up with my parents speaking Taiwanese, but it's really a tongue-twisting, infuriating language, more difficult than Cantonese. I'm glad I bought this book, however, because 1) it's very hard to find books that teach Taiwanese, and 2) it contains most things you need to know to get around in Taiwanese (thank god you can always get by with Mandarin in Taiwan). The reason why I didn't give it 5 stars is because I still think the spelling (or pinyin) could've written differently for a better pronunciation. I figured most of it out with the help of a few Taiwanese-speaking friends. Note also that the usage of words differs from person to person in Taiwan. You should totally buy this book if you're intending to stay for a long time in Taiwan and are very interested in the country. If not, I recommend taking a Mandarin-course. Much more useful and you'll be able to manage in most parts of China as well.