1. In England, pissed means drunk. In American English it means that you’re annoyed.
2. An Englishman wears pants under his trousers; an Englishwoman wears pants or knickers. An American wears underpants under his/her pants. If you want to be on a safe side, use the words: briefs, underwear and trousers.
3. Get some rest or a bath!
The English use the word toilet (both for the public and private one). Americans use the word bathroom, and in the public building – a restroom or men’s room or ladies’ room.
4. Have you knocked her up?
In America knock somebody up means to get a girl pregnant. In England, however, it simply means to wake somebody up by knocking on the door.
5. Meet me on the first floor
In the UK the floors in a building are numbered as follows: ground floor, first floor, second floor, etc. In the US, though, they start with the first floor, then the second, etc.