The ultimate aim of the ESL programs is to improve the English language proficiency of the identified ESL learners and to make them competent enough to communicate with their peers and their teachers, participate in the classroom activities and to achieve learning outcomes as the first language learners. This paper seeks to explore the various ESL programs with special reference to the different roles played by the ESL teacher, the modes of delivery of the ESL programs, the diversity of ESL learners, the key theories and ideas about second language acquisition, the planning and programming of ESL lesson sequencing and the various ESL teaching strategies employed by ESL teachers. The roles of the ESL teacher: As ESL teaching is a complex process that demands professional competence, dedication and a sound knowledge of the various strategies and practices associated with second language teaching, ESL teachers have a pivotal role in the teaching learning process of English as a second language. One of the great challenges of the ESL teacher is to provide targeted, curriculum-based English language instruction to meet the linguistic learning needs of the students. The roles of the ESL teachers include identifying , assessing the English language competence of ESL learners and prioritizing their need for English learning support. determining appropriate modes of delivery for the school’s ESL program. planning and teaching ESL programs.