Let’s get one thing straight. I hate editing and proofreading. Hate it. With a passion.
Nor do I claim to have any expertise in the area of grammar, spelling, or punctuation. Or any skill, for that amtter. matter.
But I thought that all you budding British screenwriters who want to make it in the States might want to know some commonly misused phrases, together with some insights about American English, that I have learned on my journey so far.
First of all. Toward, or is it towards? And forward, or is it forwards?
Well, actually, it’s both. And yet…
American authors and editors seem to prefer “forward” and “towards”. As in, “to run towards” or “to go forward”. Maybe it has something to do with “forwards” being one of the dreaded adverbs.
Also, I’ve noticed some differences in punctuation.
In English English (if there is such a thing), we like to drop the final comma in a list. For example: “blue, yellow, red and green”. Not so in American English. Our cousins across the Atlantic like their commas. So in American English this would tend to be written as : “blue, yellow, red, and green”.
If I’m wrong about that, I’m sure someone will correct me.
Finally, some terms.
In America they don’t have rubbish. It’s either trash or garbage. It’s not a rubbish bin either. It’s a trash can or garbage pale (or dumpster if you’re hiding a body).
Nor do they go looking in the dark with torches. Torches in America are the burning staves you go chasing after Frankenstein’s monster with. Take a flashlight instead.
Other differences can include:
“-our” endings becomes “or” endings, e.g. “colour” (British) as opposed to “color” (American).
Ending that have “-ise” e.g. “organise” in British become “-ize” e.g. “organize” in American. Similarly with “organisation” (UK) v “organization” (USA).
Other favorite confusions include:
“aluminium” (UK) v “aluminum” (USA)
“tonne” (UK) v “metric ton” (USA)
“mummy” or “mum” (UK) v “mommy” or “mom” (USA)
An excellent article on the subject can be found here: http://en.wikipedia.org/wiki/American_and_British_English_spelling_differences
So these are just a few of the ways you can confuse or distract an American reader. I’m saying all this because that’s the last thing you want to do. You want the reader to feel comfortable that you know what you’re talking about (even if you don’t).
I’m sure there are many more of these. If I come across them I’ll let you know.
No commas were harmed in the writing of this post.
ERIC IAN STEELE 
That serial comma is, ironically, called the “Oxford comma”. And it’s recommended by the Chicago Manual of Style. To some people, mostly U of C graduates, the Chicago Manual supersedes all holy religious texts and must be obeyed upon pain of death. That being said, the use of the Oxford comma is hotly debated by American editors.
The only time I get confused is the way some UK’ers will say numbers, particularly units of currency. I actually don’t understand what you’re doing and I get so hung up on it that I forget what we’re talking about. I think you say “five and fifty” where we would say “five fifty”? Is that right? I can’t even tell anymore.
Also British English handles collective nouns differently. You all will say “The Army are” rather than “The Army is”.
Also note that I do not, as a rule, use commas correctly. I like to pretend I have my own style guide. ,,
A lot of the trouble with the UK is that dialect plays a major role in spoken communication. There are so many dialects in Britain that it can be hard to understand someone who lives only ten miles away. Actually, on a side note, that’s something else British screenwriters should watch out for. If you’re writing scripts set in the USA, listen to the way people in America construct sentences. Listen to podcasts or watch interviews to get the “feel” of real, spoken, modern American – which of course has its own dialects. There’s a whole lot of difference between someone from Yorkshire and someone from Texas!