Hello,
Although we only met once, it was really nice talking to you on our way to Jiangmen. Thank you very much for carrying the express deliveries all the time. We really appreciate that. Did you enjoy your lunch yesterday? Next time when you come by, you should just tell us your preference, and we can take you out for some wonderful dishes.
It's so pitiful that I cannot speak English and therefore cannot have an oral conversation with you. So I figure writing the letter is a good way to express myself. By the way, you speak excellent Chinese. I like you saying "Ming tian jian","bu ke qi".
When there's some spare time, I learn English in the evening. It would be wonderful if we can have a direct conversation some day.
I asked for help from some friends to translate this letter. Please kindly excuse me if there are any mistakes and you can just point them out to me, so that I can notice them down and improve my English.
I guess you have a busy life also, so I will just stop here. I hope everything goes on well during your business trip. Wish you a wonderful life and let happiness always be with you.
From,
XXX（你的名字）
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注意基本格式,称呼之后用逗号,然后正文开始.最后是from XXX （这里依照亲近程度变化较大）不过from XXX是最基本的.