ESL courses are designed to be supportive of the learner while still providing enough of a challenge to encourage and promote learning on a continuous basis. Many programs offer proficiency tests at regular intervals to keep students progressing at a steady pace.
Since most ESL courses, especially those for adult learners are very sequential, it is important for the learners to attend all classes to avoid missing key concepts and ideas. Programs will typically not allow more than a specific number of absences by the learners before they must withdraw and start the program over at the next session.