One complaint to make about many reference books on grammar is that they tend to describe a language as grammarians wish it were, not as it is written and spoken in reality. Fortunately, A New Reference Grammar of Modern Spanish (Third Edition) by John Butt and Carmen Benjamin, avoids that trap while not ignoring the Academy rules of "official" Spanish.

There are very few points of contemporary Spanish grammar that aren't covered in this 572-page text. Verb conjugation, pronoun usage, verb moods, writing rules and word order — they and plenty more are all covered in detail.

This reference book, perhaps the best English-language book of its type, is outstanding in at least three ways. First, it not only explains the grammar rules as accepted by grammarians and other language experts, is also explains how the language is used by real people and how well departures from the norm are accepted by various classes of speakers. Students learning Spanish are told which grammatical constructions they should avoid as well as which might be acceptable in speech but not in writing.

Second, this reference work is thorough, addressing subjects often ignored in textbooks. Two random examples are the use of attributive nouns (as in the phrase coche bomba for "car bomb"), which some less thorough books say don't exist in Spanish; and numerous examples of nouns made plural in unorthodox ways (such as los regímenes being the plural of el régimen).

Third, the authors explain at length the difference uses in different regions. Examples from newspapers and literature are used to demonstrate, for example, the use of vos in Argentina and leísmo in Spain. If there's any major category of information missing from this book, it's examples of how Spanish is used in the United States, but that subject very well may be worth a book in itself.

The third edition makes numerous improvements from previous editions, many of them involving changes in the Spanish language due to the influence of the internationalization of English.

This book is suitable for intermediate and advanced students of Spanish, and it is organized well enough that it would be usable by even first-year students. It belongs on the shelf — or better yet, in the hands — of anyone who's serious about the grammar of Spanish.