English Learners (ELs) are students from whom much is expected: they are tasked with mastering grade-level content while also learning English, a language in which they are not fully proficient. Mastering academic English--the set of language skills necessary for success in school--is a developmental process that takes at least five to seven years. Over time, most students who begin school classified as ELs demonstrate English proficiency and their status changes from that of an active EL to a former EL. Because of this, active ELs are concentrated in the early grades. Hence, schools and teachers need to focus educational resources in the early years to support ELs' instructional needs and set them on a path to academic success. To provide new and needed knowledge about what student and school characteristics are associated with EL success in pre-k and the early grades, this study examines attendance, grades, test scores, and English proficiency from two groups of Chicago Public Schools (CPS) ELs (14,058 students in pre-k and 16,651 students in the early grades K-3) to answer the following research questions: (1) What are the factors associated with stronger outcomes for ELs in pre-k and the early grades?; (2) To what extent can schools identify ELs who would benefit from additional support?