In order to understand the Spanish language and how it works, it is instructive to trace its roots and learn about its origins. Spanish grew and evolved from a spoken dialect that had emerged from a mixture of Latin vernacular and other languages. Over time, the language spread from a small region in Spain known as Castile to cover most of the Iberian Peninsula, and then pushed on to the Americas and Pacific islands like Philippines and Guam. Today, Spanish is the native language of about 350–500 million people, the third most-popular language (following Mandarin Chinese and English).