Dear Mr Teo,
You’ve always helped me with my homework or even other problem sums. From the start of last year, you were also really kind to everyone including me. Usually, most of the teachers just give the homework without discussing it with the students, whether they are able to do it or not. But, every time we say that we have a lot of homework, you will try to lessen the workload you give us. I will make sure that I try my best for the upcoming exams to show my appreciation for teaching me my homework and problem sums. Thanks a lot! I will not let your hard work go to vain!