The research in this dissertation describes a Grounded Theory approach to identifying critical knowledge components of Teacher Content Knowledge (TCK) and Teacher Pedagogical Knowledge (TPK) for ESL teachers who must teach reading to young English language learners, often with little literacy training The research explored how professional development sessions with ESL teachers focusing on phonological processing and phonemic awareness might result in better preparation for teachers working with English language learners. The research study implemented four PD sessions and evaluated teachers in a variety of settings. Data were collected through classroom observations, questionnaires, reflections, and informal interviews. The study involved approximately 20 hours of formal PD with six elementary ESL teachers. On-going support through the use of regular e-mails and one-on-one meetings provided additional interaction between the teachers and researcher. The significance of this research is threefold: one, the findings indicate that teacher knowledge and skill to work with ELLs is highly differential, even in small populations of teachers, such as the one described here. Two, the core components and the framework developed in this work can serve as a foundation to evaluate teacher knowledge and skill to work with ELLs. Three, the findings can provide insight into how PD sessions can be structured to help in-service teachers develop the necessary knowledge and skill to support language learners' literacy development. In this dissertation, I propose that the components identified in this research can be used as the foundation for in-service professional development that is responsive to individual teachers' needs, which I have termed "Responsive PD." The components discussed can be used to evaluate teachers on whether they possess the necessary TCK to work with ELLs. The components identified here can also be used to create PD tailored to teacher's variable knowledge and skill. This study is one step in addressing the critical need for educating teachers on ways to effectively address the growing number of ELLs in their classrooms and support the literacy development of ELL students. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]