Shut up

(Li and Rosie are at the cinema)

Li:	No, come on ... Don't do it! Don't do it!
Rosie:	Li ... She's an actress in a film, she can't hear you. And besides, it's rude to talk in the cinema.
Li:	But it's just so frustrating. Don't go into the house! Don't do it! Oh, no! I can't watch!
Rosie:	Li, shut up!
Li:	I know, he's shut her up in that house and won't let her go. She's his prisoner now ...
Rosie:	No, Li ... I was telling you to shut up. It's a rude way of saying 'Be quiet.'
Spectator:	Excuse me, will you please shut up?
Rosie:	I'm really sorry. Li, I can't take you anywhere.
Li:	Oh well look, the film is over now, anyway. Sorry about the talking, but I just get a bit carried away.
Rosie:	Well, I'm sorry I told you to shut up. It is quite a rude expression in English, but you just kept talking and wouldn't shut up!
Li:	So can I tell someone to shut up when they're making noise?
Rosie:	You can, but it's informal and can be rude. So, if you're in a formal context, you should say something like "Could you please be quiet?"
Li:	OK, so in a meeting, if someone is speaking, I won't tell them to shut up. I'll say: "Could you please be quiet?" But if I'm really annoyed at one of my friends, I can tell them to shut up.
Rosie:	Yes, although sometimes it's used when people are joking in English. Let's listen to some examples:

"I'm so tired. And thirsty. When are we going to get there? If only you'd drive a bit faster ... "
"Will you please shut up? I can't concentrate with your constant moaning."

Rosie:	So in that first example, we heard the expression 'shut up' used in a serious way. But in the second and third examples, it doesn't mean we want someone to be quiet—it means: "I don't believe you" or "Don't be ridiculous!"
Li:	So when someone says something silly or ridiculous, we can say 'shut up'. And again, we only really do this with people we know well as it's informal. You've been warned!
Rosie:	Well, one thing's for sure, I'm never, and I mean never, going to the cinema with you again.
Li:	Shut up! I don't believe you ... You love going to cinema with me. I always buy you popcorn!
Rosie:	Shut up! I always get the popcorn!
Li:	Oh, shut up.
Rosie:	You shut up ...
Li:	No you shut up.