* Individual students: Providing one-on-one support and tutoring.
* Small groups of students: Leading activities and providing differentiated instruction based on students' needs and levels.
* Whole classes: Assisting the ESL teacher with classroom management, lesson preparation, and instruction.
The specific tasks depend on the school, the teacher, and the aide's qualifications, but generally involves supporting the learning of English language skills (reading, writing, listening, and speaking).