Despite anti-immigrant and pro English-only rhetoric that has existed since before the signing of the Declaration of Independence, the U.S. today is a racially, ethnically, and linguistically diverse democracy. According to the most recent census data from the American Community Survey, roughly 20% of the U.S. population speaks a language other than English at home, the most commonly spoken language being Spanish. Indeed, the U.S. recently surpassed Spain to become the nation with the second-largest number of Spanish speakers in the world. It is no surprise, then, that Spanish is also the most commonly taught second (L2) and heritage language (HL) in the U.S. Yet, whereas there has been decades of systematic research on instructed second language acquisition to inform language pedagogy, fewer studies have empirically investigated the outcomes of classroom heritage language acquisition. Although there are indications that HL learners’ language development may differ from that of L2 learners, there is little empirical evidence on the ways in which it differs and how those differences might affect learning outcomes. In this talk I present the findings from my recent empirical work, which suggests that although there are some similarities between the two learner populations, in many respects heritage and L2 learners are opposites, whose goals and even orientations to language often differ from each other. Rather than seeing one or both groups through the lens of the ‘glass is half-empty’ I take an approach that views both as bringing their own strengths to the classroom. I conclude by discussing ways that instructors can effectively meet the needs of both groups in class, since most upper-level university Spanish courses tend to enroll both L2 and heritage learners.