You talkin' to me?

At the moment, we are asked to believe, the British are all the rage in America.

The Metropolitan Museum in New York is hosting AngloMania, an exhibition launched with a glamorous and much-discussed party. Alan Bennett's very English play The History Boys had terrific reviews on Broadway, and might conceivably become a hit. The Tony awards this year were dominated by English actors, some of whom might still win.

Some allowance has to be made for national pride in these matters, which naturally tends to inflate, when on home ground, any indication of foreign interest in our cultural products. Any French small-press production about Englishness with the word Rosbif in the title is guaranteed to be described here as "a bestseller" and its most insulting aperçus widely reported.

More than one American magazine, when running a "London groovy again" feature, has produced separate editions for the European and American markets, their indigenous productions retaining a more domestically appealing starlet on the cover. And, of course, some allowance should probably be made for the gap between the tastes of the American media elite, often Anglophile in tendency if not actually English by birth, and the mass of Americans.

All the same, America has become more interested in the outside world since September 2001. If their first, bewildered question was "Why do they hate us so much?" it has, in time, been followed up by questions about what life in the outside world is actually like.

There's an easy test to apply about how substantial this new interest is, or whether the outside world is actually being listened to. Can American writers reliably report the styles of speech of one of their nearest linguistic cousins?

From Cary Grant to Dick van Dyke to Woody Allen's inadvertently hilarious Match Point ("I was raised in Belgravia"), English audiences have been retching in the stalls at American film's idea of English speech.

Ever since Henry James, in The Portrait of a Lady, thought it advisable to explain old Touchett's line "I guess I will wait and see" with the comment "He had, in speaking, the American tone", American and English novelists have been trying to "do" characters from the opposite side of the Atlantic. It shouldn't, on the surface, be as hard as all that - but the results are rarely a pretty sight.

It's a challenge for even talented novelists with a good ear. F Scott Fitzgerald's Tender Is the Night at first shies away from the challenge, merely reporting three British nannies' conversation as "the tune of gossip as formalized as incantation" - the noise of a novelist superciliously announcing that he could do something hard, if he ever felt like it.

Fitzgerald was evidently nervous about the challenge, for good reasons. At a later point, as two characters talk, a window of the hotel is flung open "and an English voice spat distinctly 'Will you kaindly stop tucking?' " Tucking? That corresponds to no known English accent. It's much easier, for Fitzgerald, to attempt the bogus Anglicisms of a Gatsby, with his awful "old sport". In reality, that's as close as he can reliably get.

More extensive attempts to "do" the English voice start to reveal some conventions. In the title story of For Esme - With Love and Squalor, JD Salinger has a go at an upper-class English schoolgirl. If Esme sounds a little strange, it's because Salinger has fastened on one English habit, the intensifying adverb, and used it to the point of insanity: "Usually, I'm not terribly gregarious. I purely came over because I thought you looked extremely lonely. You have an extremely sensitive face… My aunt says I'm a terribly cold person. She's an extremely kind person."

There's something in what Salinger has noticed, and the English of this class do use "terribly", "extremely", "quite", as well as "awfully", "frightfully", "hardly" and so on, in ways striking to Americans. But he can't get it right: in that second sentence, read: "I came over purely because…"

And Esme, in this story, has another tendency quite unrecognisable as English speech. Repeatedly, her style is absurdly elaborate: "I'm quite communicative for my age… Do you think you'll be coming here again in the immediate future?… I'd be extremely flattered if you'd write a story exclusively for me sometime."

It isn't just that American "sometime" which is wrong, but the general elevation of vocabulary and tense. In reality, an upper-class English child would say: "Are you going to be coming back soon?" The characteristic English directness of speech has been lost in a general association between Englishness and "class", and an exclusively American notion of classiness in speech has been imposed.

Salinger is doing his best, but he can't get any further east than Katharine Hepburn, as though posh and English were on the same, uninterrupted linguistic continuum.

It's a curious fact that both Americans and English regard each other's style of talking as pompous. Americans often identify elaborate diction with class, and class with Englishness, and, against all evidence, conflate the lot.

Thomas Harris's Hannibal Lecter, identified with English speech habits and the whole European museum culture, is a bizarre example. As Martin Amis pointed out, he always talks of "purchasing" something, and says in shops that "I only require one". "I haven't felt such a frisson of sheer class," Amis wrote, "since I last heard room service say 'How may I assist you?' "

We shouldn't underestimate the subtle differences in meaning. As simple a word as "quite" means two quite different things in American and English speech. And what for us are quite ordinary words turn out to be exotic or embarrassing rarities elsewhere. I once made an American professor at a literary festival gasp in amazement by complaining that I'd been "hanging around gormlessly" all morning.

It was the word "gormless". "Well, I've seen it written down before," she explained, as if she were, to her surprise, meeting a medieval peasant. The characterising of English speech as more elaborate, or "classy", in its diction might be beloved of American novelists, but it bears no relation to reality.

In the lower ranks of popular literature, the tendency of the pompous-speaking Englishman runs rampant. There are a number of popular American genres that seem to require an English character. Sometimes, this is for rational reasons - despite what is often supposed, American novels about the Second World War or spy fiction about the Cold War usually find a place for an English character or two.

I think it was Christopher Hitchens who first pointed out that every American novel about political life in Washington is apparently required to include the British ambassador in its cast.

The habitually ineffectual or villainous role assigned to such figures has been noisily complained about over here, but one might complain more about their speech. The idea of English life in The Da Vinci Code is hilarious enough. "I was knighted," the villainous Sir Leigh Teabing explains as he prepares to skip customs and immigration on landing in Britain. "Membership [sic] has its privileges."

But it's his speech that really nails the ludicrousness. "Just because I am returning to the Queen's realm does not mean I intend to subject my palate to bangers and mash for the rest of my days. I'm planning to buy a splendid villa in Devon…"

Sometimes he sounds like an Egyptian waiter: "The good news, my friend, is that you are now in the position of power." Sometimes he sounds like an American president giving a funeral address: "The winner writes the history books - books which glorify their own cause and disparage the conquered foe." At no point, however, does he sound like an upper-class Englishman.

Regional accents seem almost impossibly difficult: when a young Scotsman in Jonathan Franzen's The Corrections says "Time to go, laddie", the line might have been written for a 1940s tourist guide. Thomas Pynchon's Gravity's Rainbow, mostly playing safe with Dick van Dyke versions of English speech - "Thinking about me Xmas shopping" - falls flat when attempting Welsh English in the character of Gwenhidwy.

Most Americans stick to what they think they know - upper-class English - with not much greater success. John Updike's ventures into English speech are reliably atrocious. In a Bech story, "Bech Swings", he can hear the music - "one of those British voices produced half-way down the throat, rather than obliquely off the sinuses, with alarming octave jumps" - but not the words: "Well, Henry, you must learn to replace ardour with art... I must say, you're a stinker to let this old fag monopolise me."

Another favourite crops up with: "Your hair is smashing. You're almost Santa Claus." "Smashing" has been amusing American novelists for decades now, with only the faintest justification.

Two good American novelists who have lived in London suggest that the problem is, perhaps, that the idiom is just too fascinating. Lionel Shriver's excellent We Need To Talk About Kevin has an American narrator, living in America, but English idioms creep weirdly into her talk. At first, it's passed off as a sort of hobby, as she draws attention to "codswallop" and, again, resorts to "smashing". But isn't it peculiar that she talks about "mobile phones"?

Douglas Kennedy's A Special Relationship comes close to getting things right, with its story of an Anglo-American marriage. The rhythms are generally right, and the observations of English life acute. But there is always a sense of the English characters acting out their nationality a little bit too colourfully, like Hugh Grant in a Hollywood film. A marriage proposal goes, rather too adorably: "Well, yes, I, uh, yes, I suppose I am."

There's no doubt, either, that English novelists have just as much difficulty in rendering American speech, and much the same false notes have a tendency to enter. Many have taken their cue from the absurd style Dickens foisted on his American characters in Martin Chuzzlewit: "Mr Co and me, sire, are disputating a piece. He ought to be slicked up pretty smart to disputate between the Old World and the New, I do expect?"

It wouldn't take much to poke holes in the American dialogue of Evelyn Waugh's The Loved One, and, even to an English ear, the American narrators of Martin Amis's Night Train and Zapp in David Lodge's Changing Places sound disconcertingly like old-style mid-Atlantic disc jockeys of the Radio 1 variety.

English writers can often "do" grossly caricatured versions of American speech, such as Kingsley Amis's renderings of "no more than averagely incredible" Southern society in his Memoirs: "Anyhow, he had them nigras in and he opened his desk drawer and he took out his six-shooter and he emptied it right on the spot and them nigras wasn't seen in Moore County no more."

English novelists are no more skilled in plausibly rendering American speech than vice versa. It's undoubtedly a delicate task: the virtuoso dialogue of the American characters in Zadie Smith's On Beauty was recognised even by most American critics. I found it utterly plausible, but even there, an American friend commented that she slips in having an American speaker say "I will do" - apparently a British usage.

Occasionally, a writer does get it absolutely right. Philip Roth is a writer of exceptional technical abilities, and a matchless ear. He had, too, the advantage of being married to an Englishwoman at one time, but even with these benefits the perfection of his English speech is astonishing.

The vision of the English mind in The Counterlife is hysterical, but there is no faulting the ear when Zuckerman, the hero, visits his appalling in-laws: "I'm sorry I haven't read your books. I don't read very much American literature. I find it very difficult to understand the people. I don't find them very attractive or very sympathetic, I'm afraid. I don't really like violence. There's so much violence in American books, I find. Of course not in Henry James, whom I do like very much. Though I suppose he hardly counts as an American. But I prefer him on television, I think, now."

The perfection of Roth's rendering is that he's caught that directness and plain, articulate speech that, next to his American characters, seems shockingly bald; he has noticed the floating qualifying clauses, particularly at the end of sentences - "I'm afraid", "I find", "I think"; and he hasn't just noticed the prevalent empty adverbs - really, hardly - but has noted exactly where they come, and how frequently. There isn't a "smashing" in sight.

It can, then, be done. But the near-uniqueness of Roth's little triumph suggests a point that goes far beyond the ability of two nations to listen to each other accurately. Normally, when we describe a novel as "virtuosic", what is suggested is a novel narrated by a stone, or told in the second person singular, or with six simultaneous unreliable narrators.

True virtuosity, in fact, lies in the simple ability to render a single line of speech in a way that sounds like a real person talking. There aren't many novelists, in reality, who can reliably do this even if the character shares their own nationality, class and position. The number of novelists who can bring off a character speaking the same language from a different country, no matter how apparently familiar the cadences and accent, can be counted on the fingers of one hand. Not so smashing, after all.