Modern Persian begins with the teaching of the Persian alphabet. It aims to provide the student with the necessary skills for social interaction, as well as a basis for the study of modern literature. The course consists of seventeen units and favours teaching by communicative and contextual learning. Most units begin with a reading exercise used to introduce an item of grammar and new vocabulary, followed by explanations and drill exercises aimed at consolidating the student's understanding. Complete with Persian-English vocabulary to all the exercises and tape recordings, this is an up-to-date textbook which can be used both by teachers or individuals wishing to learn Persian independently.
The main strength of this book is that it introduces new grammatical topics at a gentle pace (in comparison to, say, Thackston). Explanations are bare bones but sufficient, and lessons progress more or less logically, building upon previous ones. There are ample example sentences to illustrate grammatical points, exercises, and passages to test your reading comprehension.
There are a few weaknesses, too, however. Firstly, there is no discussion about stress. Word stress is pretty systematic and consistent in Persian so this is something they could have at least given a brief overview of. It would have taken up very little space but would have strengthened the comprehensiveness of the book significantly in doing so.
Secondly, ezâfe is basically never marked. Considering the author marked all other internal vowels, I don't see why they wouldn't mark ezâfe. Beginners are exactly the audience that need to have ezâfe drilled into their head constantly, so not including it seems like an odd oversight. Thirdly, although vowels are marked, there are some occasions (typos?) where they were left out, leading to confusion. For example, how would a beginner (who doesn't know any Arabic or the loanword *vojud*) know how to pronounce باوجوداين without vowel markers?
Lastly, I think including a unit on the passive would have been appropriate. They covered all of the other basic grammatical necessities, making its omission that much more glaring.
All in all, good but not great. It doesn't deal enough with phonology or mark ezâfe enough to be a good choice for a student teaching themselves Persian from scratch. It would be a decent first semester classroom textbook, though. For the autodidact, Thackston would be a better (albeit more intimidating) choice.
Simin Abrahams derived MODERN PERSIAN: A Course Book from several years of teaching Persian to students in the UK. Since the book is meant for classroom use, it is probably not the best introduction for a complete beginner who wishes to study Persian on his own. For example, the entire volume is in Arabic script, but the basics of the script are sparsely presented in a handful of pages and then rigorous introduction in written Persian begins -- presumably in a classroom one would be able to dwell on the alphabet for some time, with exercises given on handouts, before moving on to the language itself. The textbook only teaches basic vocabulary and grammar, without any cultural asides that may interest learners, but again students in a classroom would get those from the teacher as well. An appendix does teach the characteristic sound changes of colloquial Persian, which may frustrate readers of other, literary textbooks.
Now, if you already have experience in Persian through a transliteration-heavy textbook, Simin Abrahams' book can be very helpful in becoming accustomed to Persian in the Arabic script. I myself used this textbook to get a taste of Iranian Persian after studying Tajik Persian, and with that background behind me the book was entirely accessible and useful. It was fun to go through the exercises here, which often involve a great deal of writing in Arabic script, and the subjunctive is taught with sufficient examples. There is supposedly a CD for this textbook as well, but I've never come across it.
So, if you already have some Persian behind you, you might give Abrahams' book a try. For total beginners in Persian who intend on learning autodidactically, however, there is probably some better start. (I learnt Tajik from a couple of Russian-language textbooks and Baizoyev & Hayward's BEGINNER'S TAJIKI.)