Teachers across the country have their own opinions on the appropriate number of students per classroom, no matter the education level. The same can be said for ESL teachers and their students. There is a big difference between a lecture hall setting and a large classroom overflowing with students.
There are benefits to both a big and small class size. When you are teaching in an ESL program, it is more beneficial to have a larger class size. A large group of students can make it easier for others to grasp what is being taught.
With a large group of students you will better be able to pair them off or put them in small groups to complete assignments. If the group is generally a quiet one, you might want to have them get out of their chairs and wander around the room during different activities. Activities that move quickly will generate more talking from the students and help them loosen up with their peers.
However, small class sizes can allow for more one-on-one interaction. It is also easier to notice students who might not be understanding the material as well as the other students. Within a larger setting, students can sometimes get lost in the shuffle and become overwhelmed.
Whatever the class size may be, when given new material the entire class should work on the activity together. Students should be able to hear you model the new material so they know how it should look on paper and sound out loud. Once you provide a good example of the new material to the class as a whole, you can then have the students practice the material individually, in pairs, or in small groups.
Class sizes in ESL programs will vary, but teachers should aim to have a class size that they are comfortable with. For instance, an ESL class with 45 or more students can be very difficult to lead, especially if the teacher does not have an aide or teaching assistant. With a class size between 25 and 35, ESL teachers can easily split the class into smaller groups for the students to practice their material.