Faldage:

>To knock someone up:
>US To get someone pregnant
>UK ? To visit someone ? To come by and pick someone up ?

In the UK: to knock on their door until they wake up.

Now onto another difference. An incident at the Sarajevo olympics which shows just how confusing the same language can be, even when spoken by neighbours.

Otto Jelinek, Canada's federal Minister of Amateur Sport at the time, was holding a press conference to complain about some ruling by some olympic official. For some reason, Canadian reporters couldn't get there on time so they asked their American colleagues what happened. They were told that the minister was clearly quite pissed.

Unfortunately, the American "He's pissed" means he's very angry. The Canadian equivalent is "pissed off". In Canada, if you say someone was pissed it means that they were drunk. Needless to say, several major newspapers had to apologise after printing headlines, "Minister obviously drunk at press conference".