Can anyone please list me no-no words in American English ( By no-no words, I mean, the words that are not used by Americans)
Never walk into a pub in American and say "I want to bum a ***". This perfectly polite British request for a cigarette would have an entirely different meaning on the other side of the Atlantic.

Rommie

Rommie
Classic one Rommie, I quit fags last December!!!
I didn't think Americans used bollocks - WHAT, you don't have a cigarette? Bollocks, I wanted to bum a ***!
I didn't think Americans used bollocks - WHAT, you don't have a cigarette? Bollocks, I wanted to bum a ***!
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Comments
Rommie
In my opinion there are NO words which are forbidden in American English. Once upon a time, it may have been true that there were words (such as "sidewalk") which were usable only on one side of the Atlantic, and other words (such as "pavement") which were usable only on the other side. I don't believe that is the case any more. This is the age of the internet. This is the age of satellite TV. Those old days are gone, and they're not coming back.
To clarify what I mean - traditionally, Americans don't use the words "lorry", "timber" or "motorway". (They say "truck", "lumber" and "freeway"). Nonetheless, if I was to write a novel about a hero who drove a lorry full of timber down a motorway, I guarantee that by the time my American readers got to the end of the novel they would know what those words meant, and will have added them to their vocabulary.
The main thing you want to watch out for is not vocabulary, it is spelling. When you cross the Atlantic, spelling rules change. This is unfortunate because, unlike introducing a new word to the vocabulary, the "wrong" spelling of a word does you a dis-service. It makes the reader think "that bugger can't spell". My advice here - set your spell-checker to American and leave it there. The vocabulary is not really a problem.
Rommie
*** you