I'll miss you. 我会想你的。
I wish I could go with you.我真希望能和你在一起。
Give me a call sometime.有空给我打电话。
Call me sometime. 有空打电话。
Let's get together again sometime. 我们什么时候再聚吧。
Let's keep in touch. 保持联系。
Don't forget to write. 别忘了写信。
Please give my regards to your family. 请代我向你的家人问好