My line of inquiry explores three interrelated avenues in the field of Spanish Applied Linguistics: language education, language learning, and language in society. I examine how contextual factors help to understand differences in Spanish second language (L2) and heritage language (HL) acquisition, and, more specifically, how L2 and HL learners develop their (socio)linguistic competence in different contexts, e.g., in an at-home classroom, through study abroad experiences, in electronic and community service-learning environments, and in both pre-service and in-service teacher education programs. This research incorporates current theories and methodologies in sociolinguistics and L2 and HL acquisition to examine language variation among native and nonnative speakers of Spanish. To this end, I employ quantitative methods to uncover the social and linguistic factors that shape Spanish at the individual and societal levels. More recently, I have also explored current issues in Spanish as a heritage language in the United States and Spanish for Specific Purposes.