It's well-known that"England and America are two countries divided by a common language" but I wonder how many people realize that even the simplest words can have different meanings and be cause for confusion.
These are some examples:
anxious: Most Americans would use the word, anxious to mean they are eagerly looking forward to something whereas most Brits use the word to mean they are worried or dreading something.
Homely: in America homely refers to a person who is physically unattractive (ugly) whereas it has a completely different meaning in Britain where homely means down-to-earth and welcoming. A person and/or their home can be called homely and it's a compliment!
pavement: To Americans the pavement is the road surface while in England, the pavement is what you walk on (Americans call it the sidewalk).
There are also difference in spellings such ss pernickety (British spelling) and persnickety (American spelling)or titbit (British spelling) and tidbit (American spelling), hotchpotch (British spelling) or hodgepodge (American spelling).
Sometimes it's the preferred use of a word that is very noticeable:
Americans say almost, Brits say nearly
Americans say cute , Brits say lovely
Americans say awesome, Brits say brilliant
Americans say Good job!, Brits say Well done!
Americans say garbage, Brits say rubbish
Americans say faucet, Brits say tap
Americans say shopping cart, Brits say trolley
Americans say watch out as a warning, Brits say mind.
And completely different words that have different meanings:
A flashlight is called a torch in England.
A sweater is called a jumper.
A jumper is a type of dress in America but is a pinafore dress in England.An undershirt is a vest and a vest is a waistcoat.
Pants are trousers in England.
Underwear are called pants.
A headband is an Alice band.
Pigtails are called bunches and (hair) braids are plaits.
A barrette is a slide.
A stingy person would be called mean in England.
Pudding is dessert.
Paper towels are kitchen towels.
The principal is called the headmaster or headmistress.
The substitute teacher is called the supply teacher.
A wrench is a spanner.
A wading pool is called a paddling pool in England.
To knock on wood for luck, is touch wood in England.
When speaking about sports in England such as bowling, you need to specify that you mean ten-pin bowling, not lawn bowls, since both types of bowling are popular. And to add to the confusion most Americans would assume a Brit means ice-hockey not field hockey when a Brit talks about hockey.
To be "kitted out" means to be dressed in the appropriate outfit. To be "vetted" means to be checked out before you are hired for a job.
When referring to buildings, the first floor in America is the same as the ground floor but in Britain, the first floor is what Americans call the second floor!
Sometimes it's the use of popular brand names that are used as everyday words. For instance, the Brits refer to vacuuming as "hoovering" and ball point pens are called a "biro", and clear sticky tape is called "sellotape" (Americans call it "scotch tape"). Another example of a brand name used for an everyday product in America is "Saran wrap" which the Brits call cling film. A plaster is called a Band-aid in America.
There are some very British expressions that don't mean anything to Americans such as a "nosy parker" which is just another name for a nosy person. To "suss out" someone or something, means to figure out. A "row" (rymes with cow) is an argument. Workers hired to do building work and who botch the job and don't do the work they are hired for are referred to as "cowboys". A fortnight is another word for two weeks (fourteen nights).
Is it any wonder that sometimes there is a moment of confusion or wild misunderstandings from Americans in Britain and vice versa, from Brits in the USA?
Edited (on 22 Dec. 2010) to add:
I've written about just some of the many differences between American English and British English. If you want to learn more about this fascinating subject, I recommend this excellent blog which is devoted to the subject:
Separated by a Common Language written by Lynne Murphy, an American linguist in England.