I have to leave.=I have to go=I had better take off.
我该走了。
A:I have to leave.
我该走了。
B: Can't you stay a little longer?
再待会儿不行吗?
It's to a bad you have to leave so early.
你这么早就走啊。
It's still early.
还早呢。
It's not late yet.
还早着呢。
Why don't you stay a little longer?
怎么不再多待一会儿呢?
Do stay a little longer.
再多待一会儿。
Can't you stay a bit while?
你不能再待一会儿吗?
A:I've got to go.
我得走了。
B: Why don't you stay a little longe.
怎么不再多待一会儿呢?
I hope to see you again.
希望能再见到你。
I hope you’ll be able to come again. when you're free.
希望你有空再来。
I hope you can come around again.
希望你再来。
I hope you'll drop in again whenever you're free.
希望你有空就来坐坐。
A: It's getting dark.I can't stay any longer.
天快黑了。我不能再待了。
B: I hope you'll drop in again whenever you're free.
希望你有空就来坐坐。
drop in“不预先通知的拜访”
I won't keep you then.
那我就不留你了。
A: I really can't stay any longer.
我真的不能再待了。
B:I won't keep you then.
那我就不留你了。
I'll miss you.
我会想你的。
A:I'll miss you.
我会想你的。
B:I'll miss you,too.
我也会想你的。
Let's keep in touch=Keep in touch.
让我们保持联系。
A:Let's keep in touch.
让我们保持联系。
B:OK.
好的。
keep in touch“保持联系”