Instruct: Classify Amazon reviews into positive or negative sentiment
Query: For someone wanting an introduction to Persian don't bother.

For a scholarly detailed and obscure grammar look no further. If you want a guide to how Persian was written in the 10th century your on to a winner. For those who know Arabic, this work is comparable to Wright's grammar with little excercises and unbearably long vocabulary lists at the end of every section, followed by a collection of largely unannotated prose passages at the end of the book. The last half of the book is dedicated exclusively to explaining Arabic grammar that the student of the modern language scarcely needs. Alas I have never got that far. Every time I've picked up this tome, I've put it down again before completing Chapter 10. This book is for the advanced student only, and the more pedantic one at that. Beginners use Thackston, you won't regret it.