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.
Colleges and universities that offer an ESL course may not offer credits to students for completing the course. This is important to consider as it may be possible to take the ESL course before starting to pay tuition to the college or university, depending on several different factors.