Book excerpt: Spanish is a pluricentric language, meaning that it has several centers of prestige (e.g., San Juan, Buenos Aires, Mexico City, and Lima). Moreover, Spanish, like all languages, evinces socio linguistic variation, in that levels of formality are expressed through the use of different structures. Given this variety, students of Spanish will inevitably come into contact with variation in Spanish. This variation in Spanish adds layers of complexity to the learning and instruction of the Spanish language; therefore, a linguistic understanding of variation is crucial for our students to achieve communicative competence. This unique work, which provides an overview of the most important linguistic aspects of Spanish within a context that recognizes variation, assumes no prior linguistic knowledge and is appropriate as a valuable resource manual for teachers and learners of Spanish alike.