Li NanDear sir :
I am very glad that you are my teacher,You are one of the best teachers who I know .there are many good points what we should learn from you,such as kindness,patience,humor and so on.please forgive me that I had made so many mistakes which make you always angry.I really want to be a good student.Thanks for you teaching ,I have learn so many interesting things ,so many words,so many sentencesform you,Ican feel that it is not only a progreof learning,but also a convarcation of feeling 。 You are my teacher and good friend, We are the lucky dogs that we have such teacher as you.finally，I hope you happy everyday!
best wishes
your student
dd mm yy
Dear teacher ,
I am writing to you to express my thanks for your help in learning English and speaking English.
During these days in your class, I have learned much from you and it is very helpful to me. Firstly, you let me know what is the west thinking pattern—straight thinking pattern. And, I think, it is very important to understand the west’s thoughts. As you know, this can help me with my examination and interaction with foreigners. Secondly, I have got enough confidence in speaking in English from your class and it took me a long time to gain this confidence. Now, I always express my ideas in English as possible as I can. It’s great to do that. The last not the least, I find that learning English is not an boring thing as before and I’m interested in studying English which was just a necessary task to pass examinations. Reading, listening or speaking all become interesting and I really enjoy it.
Above all, I want to say thanks again to you. And thank you for your time.
Good luck ^_^