This volume compares the evolution and current status of two of the world's major languages, English and Spanish. Parallel chapters trace the emergence of Global English and Spanish and their current status, covering aspects such as language and dialect contact, language typology, norm development in pluricentric languages, and identity construction. Case studies look into the use of English and Spanish on the internet, investigate mixed and alternating lects, as well as ongoing change in Spanish-speaking minorities in the US. The volume thus contributes to current theoretical debates and provides fresh empirical data. While offering an in-depth treatment of the evolution of English and Spanish to the reader, this book introduces the driving factors and the effects of the emergence of world languages in general and is relevant for researchers and students of sociolinguistics, historical linguistics, and typology alike.