Feifei: Hello and [bad word] to The English We Speak, I'm Feifei. And, as usual, I'm waiting for Neil, who's late. I think I'm going to get some revenge by playing a few jokes on him - especially as he forgot my birthday yesterday.

Neil: Hi there, sorry, I'm late. [bad word] to The English We Speak, I'm Neil and with me today is Feifei.

Feifei: I've done all of that.

Neil: OK, how are you, Feifei?

Feifei: Not... good...

Neil: Oh dear. What's the matter?

Feifei: I can't believe you forgot.

Neil: Forgot? Oh no, what have I forgotten?

Feifei: What haven't you forgotten? Well, for a start, you were supposed to meet me an hour ago.

Neil: Really? I thought I was only five minutes late.

Feifei: An hour and five minutes late. Secondly, you were supposed to be dressed smartly as we are meeting that very famous guest later.

Neil: Famous guest?

Feifei: Yes, our very famous guest.

Neil: Who's that, then?

Feifei: How could you forget that Justin Bieber [bad word] in?!

Neil: What!? My hero, Justin Bieber?! Where?! When?! Hang on a minute, Justin Bieber [bad word] in. I wasn't born yesterday, Feifei.

Feifei: You weren't born yesterday but I was - well, twenty-something years ago. It was my birthday! And you forgot! In English, if you want to tell someone that they haven't made you believe an obvious lie, you can say I wasn't born yesterday. Here are some examples:

A: Did you know that I was the third man on the moon?
B: I wasn't born yesterday. You're British and I know that no British people have walked on the moon.

A: (Radio advert) [bad word] in 3 days with just one minute's study an hour!
B: Those adverts are so stupid! The only way to learn a language is years of hard study and practice. I wasn't born yesterday.
Feifei: So, you can say "I wasn't born yesterday" to show that you are not easily fooled.

Neil: And I wasn't born yesterday, so I know that Feifei's claim it was her birthday yesterday isn't [bad word] 

Feifei: No, that bit is [bad word] 

Neil: Yeah, right. As I say: I wasn't born yesterday.

Feifei: I was! I really was born yesterday. I had a party and everything. Where's my card and present?

Neil: You're not going to fool me.

Feifei: Argh, you're so annoying! I never forget your birthday, Neil.

Neil: I know it wasn't your birthday yesterday...

Feifei: It was!