This book is what is called a “reference grammar”. It attempts to expound the whole Lojban language, or at least as much of it as is understood at present. Lojban is a rich language with many features, and an attempt has been made to discover the functions of those features. The word “discover” is used advisedly; Lojban was not “invented” by any one person or committee. Often, grammatical features were introduced into the language long before their usage was fully understood. Sometimes they were introduced for one reason, only to prove more useful for other reasons not recognized at the time.
By intention, this book is complete in description but not in explanation. For every rule in the formal Lojban grammar (given in Chapter 21), there is a bit of explanation and an example somewhere in the book, and often a great deal more than a bit. In essence, Chapter 2 gives a brief overview of the language, Chapter 21 gives the formal structure of the language, and the chapters in between put semantic flesh on those formal bones. I hope that eventually more grammatical material founded on (or even correcting) the explanations in this book will become available.
Nevertheless, the publication of this book is, in one sense, the completion of a long period of language evolution. With the exception of a possible revision of the language that will not even be considered until five years from publication date, and any revisions of this book needed to correct outright errors, the language described in this book will not be changing by deliberate act of its creators any more. Instead, language change will take place in the form of new vocabulary — Lojban does not yet have nearly the vocabulary it needs to be a fully usable language of the modern world, as Chapter 12 explains — and through the irregular natural processes of drift and (who knows?) native-speaker evolution. (Teach your children Lojban!) You can learn the language described here with assurance that (unlike previous versions of Lojban and Loglan, as well as most other artificial languages) it will not be subject to further fiddling by language-meisters.
It is probably worth mentioning that this book was written somewhat piecemeal. Each chapter began life as an explication of a specific Lojban topic; only later did these begin to clump together into a larger structure of words and ideas. Therefore, there are perhaps not as many cross-references as there should be. However, I have attempted to make the index as comprehensive as possible.
Each chapter has a descriptive title, often involving some play on words; this is an attempt to make the chapters more memorable. The title of Chapter 1 (which you are now reading), for example, is an allusion to the book English As We Speak It In Ireland, by P. W. Joyce, which is a sort of informal reference grammar of Hiberno-English. “Lojbanistan” is both an imaginary country where Lojban is the native language, and a term for the actual community of Lojban-speakers, scattered over the world. Why “mangle”? As yet, nobody in the real Lojbanistan speaks the language at all well, by the standards of the imaginary Lojbanistan; that is one of the circumstances this book is meant to help remedy.