How Do I Get an ESL Endorsement in Illinois? If you are a certified, practicing teacher in Illinois, you are ready to begin the process of getting an English as a Second Language Endorsement. Teachers of the English language learners work with students from pre-kindergarten through high school who are not native English speakers. An ESL teacher provides lessons and support to those students. Often, teachers work one on one with students or in small groups, but they may have classes of mixed ages and differing linguistic backgrounds. ESL teachers bear the same responsibilities as regular teachers — lesson planning, grading and assessing, meeting with parents — but they must also find creative ways to help students grasp the complexities of the language and culture, tapping real-life scenarios to make learning meaningful.