1.Excuse me/Pardon me,but did you see
anyone looking for a wallet?
或：…, did anyone/someone come to look
for/ask about/looking for a wallet?
或：…, has anyone been here to look for…?
或：…, but have you seen anyone/someone
looking for a wallet/purse?
或：…, you've seen someone looking for a
wallet/purse,haven't you?
2.Could you find him and give it back to
him…?
或： Can you find him and give it
back/return it to him…?
或： Will you be able to…?
或： Do you think you can/could/will be
able to…?
3.Do you mind if I leave the wallet with
you/at your place?
或：… if I put the wallet/purse at your
place?
或：… if I hand it in to you?
或： Do you mind keeping the wallet/purse
for him?
或： You will/would/do not mind
if…,will/would/do you?
4a.That doesn't matter.
或： That's not important.
4b.I've only done what I should.
或： I (only/just) did what I should (do).
或： That's what I should do.
5a.It's getting late/dark.
或： It's late.
5b.I must be going now.
或： I'm afraid/I think I must be going
/leaving/off now.
或： I'm afraid/I think I must go/leave/be
off now.
或： I think/I'm afraid I've got to
go/leave now.
或： I must leave/go now.