Thank you for your reply Dr. ZacK!

More info:

Classes are in the morning 6:30am to 8am (before work). Students are professionals most of them. Age: from 16 to 60 years old. I've tried memory games, have them make a circle (seated) then asking each to mention an item and then repeat all the items mentioned by the others. Their level is from very beginer to able to communicate a few words. Also, I teach on the phone as part of the class, 20 minutes each 2 times a week.

Ideas welcome!! Nat