I am writing to you today to thank you for teaching a great online course. You made this dry subject and serious knowledge interesting and fun, and I really loved taking your class and learning so much on this course. I want you to know that you have been my favourite teacher since the course began. You not only taught in a different way to make us interested in learning, but you also understood our problems and helped us find the best ways to solve them.
I will surely miss you and things you taught us.
Thanks and regards