This study investigates the learning of linguistic structures associated with African American English (AAE) among four non-AAE-speaking teachers of AAE-speaking students. It considers implicit and explicit learning/development of a second dialect in two novel ways. First, it focuses on the understanding of a socially-stigmatized dialect by speakers of a socially-valued dialect, the language of the classroom. Second, it considers the knowledge of individual AAE features by outgroup speakers, about which little, if anything, was previously known. This research highlights the linguistic situation in one urban high school over the course of an academic year, focusing on four teachers' proficiency in their students' dialect as demonstrated by teacher performance on a translation task administered four times over the course of an academic year. Results indicate that features cluster into three levels of proficiency, with the highest level attained by the teacher who was most deliberate and explicit in her second dialect (D2) development. This work contributes to the small but growing canon of research on D2 development.