Dear Mr John,
How are things going with you in Beijing?
I am writing to show my thanks to you. You tutored me in my spoken english before you went to Beijing. With your help I made such rapid progress that i won the first place in the spoken english competition of the city. My achievement is owed to your help. Thank you very much.
I have heard that you and your wife will pay a visit to my school. I am very glad at the news.In that case we can see each other again. I am looking forward to your coming. I am sending you a telescope as a small gift. I hope you will like it.
All the best.