"It's like, 'Hi, my accent is really mangled and I don't know where I am, it's like I'm in the middle of the Atlantic,'" says Suzanne Levy, a British TV producer. Adds Paul Foulkes, a lecturer in linguistics at the University of York, "Oh, God yes. Horrendous."

Mr Grossman, an American who grew up in Massachusetts, has, to many British ears, a fake British accent. He's not the only one, either. After buying a home in London and marrying the British film director Guy Ritchie, Madonna went British, too, at least over here. So have many less notable Americans. Some attempt a complete linguistic makeover. Others merely start saying "bloody", "cheers" and "indeed" a lot - often to the amusement of Britons. "Sometimes an American will be speaking completely in an American accent and they'll say 'when I went and had a bahth '," says Ms Levy. "What?"

The irony, says Khalid Aziz, a British communications specialist, is that "the British actually quite like American accents and find it quite highly associated with success in business." His company, Aziz Corp, recently completed a survey that found that 47% of British business directors interviewed considered executives with an American accent more successful than those from many British regions. "What we advise Americans to do is not try to give up their American accent, but stick with it," he says.

The trouble for adult Americans in Britain, language experts say, is that because of changes in the brain, only young children can fully master a new accent. "If a kid moves to a new area after 14, that kid will never sound like he or she belongs to that area," says Jack Chambers, a professor of linguistics at the University of Toronto.

Experts call the phenomenon of adjusting one's accent to new surroundings "linguistic accommodation". Some of it occurs subconsciously, with people "just responding to what they hear around them", says Dr Foulkes, who notes that vocabulary usually is the first to change as that's easier to do. Whether one goes further, and begins to change the pronunciation of words, depends on a variety of hard-to-measure factors, especially attitude.

Many Americans view British accents - at least the ones they hear on television, in films and on the radio - as more sophisticated, cultured and prestigious than theirs. That may be because, even though there actually are a multitude of different British accents, Americans are most familiar with "proper" accents such as the so-called Oxbridge variety ...

Upon moving to Britain, some Americans can't seem to resist the temptation to adopt a British accent, even if they're doomed to failure. "They're sending out a signal of some kind," says Dr Chambers. "It may be insecurity - they want to fit in... It may be alienation from the homeland... It may be as simple as they want to sound like they're hosting Masterpiece Theater [a US programme known for showing adaptions of British literary classics]."

Still, there's a whole camp of Americans here who do resist... Brian Henderson, an American investment banker who has lived in London for three years, says he wouldn't think of switching. "The last thing you want to do is... be pretentious and pick up a British accent," he says. "It's so obvious."

At the other extreme, there's the writer and National Book Award winner Andrew Solomon, a native New Yorker. He confesses that he attempted to mimic a British accent even before he moved to Britain in the 1980s to go to Cambridge. "I find that it's very useful to have lived in Britain because it gives me a good excuse to have the same affected accent I had in the first place," he says. "I think I had some notion that it was grand and aristocratic and as I was not going to distinguish myself athletically, I thought I would distinguish myself with my enunciation"...

But Solomon says there's no going back. Even though at times he has thought to himself, "This really is silly. I should really sound more American," he says, "it would take such an enormous self-conscious effort to sound profoundly American again, then that seems affected." Besides, he adds, his speech isn't nearly as affected as Mr Grossman's. Says Solomon: "His accent is so ridiculous, it makes me sound like a hardy stalwart from Brooklyn."

Mr Grossman declined to comment for this article. Madonna - who drew snickers two years ago when she announced the winner of the Turner prize in a distinct British accent - also declined to comment. But her spokeswoman, Liz Rosenberg, wrote in an email, "She does naturally pick up on languages and sounds of people around her... It's certainly not meant as an affect... When she's back in New York for a while, she gets right into the New Yawk sound."

What about Britons who move to America? Do they want to sound American? "When I open my mouth, people say, 'Oh, my gosh. You're English. That's so nice,'" says Julie Kleyn, a Briton who lives in Massachusetts. "So why should I change my accent?" Her three sons, on the other hand, quickly adopted American accents when they moved to the US three years ago, but only when speaking among their friends... This is typical of children because they "don't want to be different", says Dr Foulkes.

Ms Levy, who recently moved from London to New York, says she has begun adopting some American expressions "because, frankly, I can't take that look of total incomprehension when I know that I speak the language better than anyone in this country". She says, "One of the biggest changes is if I'm in London and I'm trying to hail a taxi, I say, 'Excuse me! Excuse me!' Whereas here I have to say the really embarrassing, 'Yo!'"

· From the Wall Street Journal, September 30 (www.wsj.com)