who
Who is it?
用;有人敲门时问的话。有时电话上也用此语问对方是谁，但用法稍嫌无礼。一般客气地问May I know who's calling?或May I know (ask) who(m) I'm speaking with?(请问你是哪位?)
意：谁啊?哪一位?
例，A: Who is it?
谁啊?
B: It's me, Iill.
是我，吉尔。
A: Oh, Please come in!
啊，请进!
A: Hello, could I speak to Portia?
喂，请找波西娅。
B: Who is this? She's not in!
谁啊?她不在!
who （what） should.（but...)
用;对某人某事感到意外或惊讶的句式。
意：竟会…;怎么会…;偏偏…
例，At that point, what should happen but the car refused to start.
就在那节骨眼儿，偏偏车子发动不起来了。
A: Who should I meet on the plane but .Tack Keynes.
在飞机上我想不到竟会碰见杰克·凯恩斯了!
B: Gash, really?
天啊，真的?
