It isn’t simply a question of spellings - behavior, organization, center and color are among the more obvious differences. There are more subtle differences too, which are much more easily missed. Writing the date is something we learn to do in primary school and it becomes second nature. Writing the US version, Feb 17, rather than 17th Feb, is a step that has to be consciously remembered.
There are further complications when it comes to vocabulary. On my first visit to an American theme park, I was puzzled to see a sign saying “No strollers” next to some of the attractions. I assumed that this must mean that you had to move swiftly through that area. And on my first teaching assignment in California, I asked a boy to place a wrapper in the waste paper basket and the class roared with laughter. I mentioned aluminium in a science lesson about metals and was met with blank looks. When I asked the stationery office for drawing pins, the hairdresser for a fringe trim, and a waiter for the bill, I was met with similar vacant expressions.
Of course, by the time I left the US two years later I was speaking like a local, with “trash”, “aloominum”, “thumb tacks”, “bangs” and “check” rolling off my tongue so naturally that I sounded ridiculous to my friends on returning to the UK. But these adjustments felt like a necessary survival skill at the time.
I’m now working on another assignment that requires American English. It's a short detective story by an Italian author - not quite my usual remit, but there is a scientific element (without giving anything away). I'm delighted to be doing this, but I’m now 20 pages in, and already there are questions arising. “Scambiare due chiacchiere”, for example. Although we Brits might say “have a chat”, that doesn’t sound too American. Yet “go speak with them” doesn’t have the same effect.
Meanwhile, “qualche biscotto accompagnato da un caffè” when translated as “cookies with coffee” does not convey the lovely feel of someone taking a leisurely breakfast on the balcony that I wanted to share. Even the numbering system in buildings has a few problems. “Secondo piano” would be “second floor” in English - that is, two above the ground floor - whereas in American “second floor” is the one above the lobby; one up from the ground. So precisely where is this room? I would welcome suggestions...