I'll miss you. --I'll miss you, too. 我会想你的!
I'm gonna miss you.
I wish I could go with you. --So do I.
我真希望能和你在一起.
Please give my regards to your family.
请代我向你的家人问好!
I will. They asked me how u were doing.
You must come back. 你一定回来啊.
Give me a call sometime.有空给我打电话.
Call me sometime.
Thank you. I enjoyed it very much.
Let's get together again sometime.
我们什么时候再聚吧.
Please write me a letter. 请给我写信.
I'll write you a letter. 我会给你写信的.
Let's keep in touch. *keep in touch with... 让我们保持联系.
Will do.
Let's keep in touch with each other.
Don't forget to write. --I won't.
别忘了写信.