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.

This revised and expanded edition of Ralph Penny's authoritative text includes new material on the nature of linguistic history, the concept of World Spanish, processes of convergence and divergence in Spanish and the English/Spanish interface. This edition also contains a glossary of technical terms, guidance on further reading and suggested topics for discussion.