Massive Open Online Courses (MOOCs) offer high quality, free courses to anyone with an Internet connection. However, these courses may be relatively inaccessible to the large global population of students who are English Language Learners (ELLs). Current efforts to understand student motivation in MOOCs do not take into account the specific needs of ELL students. Through interviews with 12 ELL online students, and a survey with 20,084 ELL respondents, we investigate ELL students' motivations for taking online courses. We show that ELL students' motivations are highly socialized strategies for achieving long-term goals of economic, social, and geographic mobility. Although research studies show that ELLs interact sparingly with other students in MOOCs, we present evidence that they have unmet needs for interaction, and discuss how student interaction systems in MOOCs can better address these needs. Finally, we show evidence that ELLs deliberately use English MOOCs to improve their language skills, even when the content is not language-related. This implies that meeting ELL students' needs and access to MOOCs involves translating MOOCs to their local languages, but also providing language support in English-language MOOCs.