This dissertation analyzed how exemplary mainstream teachers of English Language Learners (ELLs) taught these students across contexts—English monolingual immersion and bilingual. The research for this study was grounded directly in the teaching practices of exemplary teachers for English Language Learners (ELLs). Teacher participants undertook inquiry into their own practices to provide the knowledge and information needed to assist other teachers in improving their practices with ELLs. The research in this case drew upon previous research in the area of professional knowledge and expertise. The major goal was to understand from a holistic viewpoint the successful teacher of ELLs—their backgrounds, knowledge and practices, and how these were mediated by teaching contexts—English monolingual immersion and bilingual.

Using a constructivist grounded-theory design, four descriptive case studies were the focus of the dissertation. Using interviews, observations, recall sessions, and a focus group, each teacher was studied to determine their backgrounds both personally and professionally, teaching practices, and attitudes towards ELL students, in order to create a theory of what it takes to be an effective teacher of ELL students.

The results suggest that certain background experiences can positively impact the teaching of ELL students: learning a second language, being immersed in a culture different from one's own, and an understanding of second language development. The results also indicated common patterns among the teachers' planning and preparation, teaching practices, and attitudes towards their ELL students. Commonalities in teachers' planning and preparation included the use of themes and units, language goals for their ELL students, knowledge of students' backgrounds, and preparation of exemplars and models. Commonalities in classroom practices included repetition of key vocabulary and phrases, prompting and coaching ELL students, thoughtful grouping and pairing, frequent check-ins with ELL students, and, in the bilingual context, use of the students' first language for learning and instruction. Finally, all of the teachers demonstrated common observable attitudes towards their ELL students such as kindness, sensitivity, and encouragement.