You look like someone I know.
你跟我一个朋友长得好象。

Haven't we met before?
我们之前见过吧？

That's a great haircut.
你的发型很棒。

(To the bartender) I'll have what the handsome gentlman (beautiful lady) is having.
（对酒保说）我要跟这位帅哥（美女）点一样的东西。

Can I buy you a drink?
我可以请你喝一杯吗？

You have a great smile.
你的笑容很美。

Are you here alone?
你一个人在这儿吗？

What's a handsome guy (pretty girl) like you doing here alone?
像你这样的帅哥（美女）怎么会落单？

What do you say we go somewhere quiet...
我们另外找个安静的地方如何……