This book studies the differences of pronunciation and grammar that exist within the Spanish-speaking world, and traces their origins in the frequent mixing of dialects in Spanish-speaking communities from the Middle Ages to the present day. It emphasizes the subtlety and seamlessness of language variation, both geographical and social, and shows how the constant process of mixing has rendered Spanish particularly subject to leveling of its linguistic irregularities and to simplification of its structures, both in Europe and later in the Americas.
Much more than a book on Spanish this book gives valuable insight on how change operates on languages and everything is written in a manner that can be understood without specific linguistic knowledge. All that I expected and more. The only thing that's still missing for me is an explanation on why latin evolved in this particular way in the Iberian peninsula (latin with a vandal accent?) but that's probably mostly speculatory and this book is not about speculation. Anyway, if anyone can give me a title of a book speculating on the above and/or a similar book on German, English or French I'd be greatful.