"We are two great nations, separated by a common language"I love the Americans, they're great folks, and have an absolutely great sense of humour. It is just unfortunate that they do not have a good command of English though. I can hear the jeers at me now, well if you're unconvinced, allow this 'non-native speaker of English' to teach a thing or two on how bad American English is, and take a rib at them with a few examples:- Winston Churchill, on America and Britain
1) They refuse to understand "mobile phone" as "cell phone"
There was this time when I was at a hotel in San Mateo talking to the concierge, when we found out that one of the members in our group went missing. So I told the lady at the counter to hold for a second, while I call my colleague on my mobile phone, and she went 'Excuse me?!', in her loud, American fashion.
An English colleague of mine kindly stepped in and reiterated what I've said, replacing it with a 'cell phone', and turned back to me and said semi-jokingly, 'mobiles only mean those things that they hang from the ceilings here'.
From a Singaporean perspective, we could be worse, since we proudly call them 'handphones', which is literal transmogrification of the word from Chinese to English! In this case, we're one up the Americans already!
2) They do not understand what a "fortnight" is
This one's a real gem, because it came from a well educated and rather senior banker. To cut the story short, when someone in my office used the word 'fortnight', the guy had to do a double-take, and only after a while later did he overcome his embarrassment and asked what that meant, not knowing that it's just another way of saying 'half a month'!
3) Takeaways are "to go's"
This happened to me on my first trip to MacDonalds. The girl at the counter asked, 'having it here, or to go?'
Innocently I replied, 'to go where?'
4) They call "full stop" a "period"
The Americans are embarrassingly wrong in this case! A "period" is one of those sexist thing that only a woman can have. It comes once a month, and they get pretty twitchy whenever it happens. But remind me not to be this explicit when explaining to my bosses' 9-year old, who pointed it out to me!
5) Bills and checks
They don't call a bill "a bill". Instead they call it "a check". Well usually if I ask anybody for "a check", I'd expect to bring it to the bank and exchange it for cash. Who says Americans aren't generous, when they are quite happy to give you a check instead of making you pay for a meal?
6) They don't "take a turn", but instead they "make one"
This is one of the weirdest usage of English I've ever encountered. Whenever Americans give directions, they won't tell you to take a left turn down the block, but instead you'll have to demolish a few buildings and pave your own pathways by 'making a left'. I'm still holding off on my temptation to reply, "but I haven't got the tools!"
7) They don't apologise when they bump into you
I'm not saying that Americans are offensive or rude. They are just more accustomed to using "excuse me", when they want you to move aside, rather than "sorry" when there isn't a need to. The Aussies and the Brits are "more polite" in this respect, and more prone to using "sorry" than "excuse me".
8) What's a biscuit? And a boot?
This is one of the instances that I'm more in agreement with my American friends. I'm quite fine with swapping the usage of a biscuit and a cookie, they don't mean anything materially different to me, but in the case of a car, the trunk (as in a suitcase) makes more sense than a smelly old boot (that people wear on their feet).
9) They can't spell people's names
They spell 'Bill' as 'William' , 'Bob' as 'Robert' and 'Chuck' as 'Charles'. No wonder TV shows like 'Are you Smarter than a 5th Grader' are so popular in the US. These shows will probably just have very limited appeal everywhere else in the world!
10) They are bad at pretending French
I was out on those weekend markets one day, looking at some sweet potatoes, when the lady serving me said, "these goes well with 'erbs". That got me confused for a while, like what are 'erbs'?
Only after a while did it strike me that she meant 'herbs'!
Gosh, even the English know better than to have a silent pronunciation at the first consonant of the word! So will all you pseudo-French-Americans out there, learn this:
'In Hartford, Hereford and Hampshire, Hurricanes Hardly ever Happen. HaHa, HaHa!' 
 Quoted from Professor Higgins, in the movie 'My Fair Lady'. Ok, I added the Haha part. But hey, you don't laugh without your 'H's do you?