Do you growl, roll or trill? The letter ‘r’ – and how we pronounce it – reveals a surprising amount about identity, fashion and history, writes James Harbeck.

The ‘r’ sound is the Doctor Who of speech sounds: it’s really several, obviously different sounds that we treat as the same because they play the same role. But which ‘r’ you use says a lot about who you are, where you’re from, and who you want to sound like. 

More like this:

–        The rebirth of Britain’s ‘lost’ languages

–        Seven Japanese words to live by

–        Fourteen words that define the present

Three-quarters of the world’s languages have at least one ‘r’ sound – what linguists call a rhotic. The problem is that the rhotics seem to have very little in common: they’re said anywhere from the far back of the mouth to the lips, and the tongue may be trilling, tightly constricting the airflow, loosely constricting it, or doing very little indeed. And yet we generally recognize them as versions of the same sound. The French uvular ‘r’, for instance, is what we consider the classic French ‘r’– think of how Hercule Poirot says his own name. The German version of the uvular ‘r’ is a little different because it drops off completely after vowels – think of how Arnold Schwarzenegger says his own name or the classic line from Kindergarten Cop, “It’s not a tumour!” (“It’s not a tumah!”)

Linguists argue about what all the ‘r’ sounds have in common; recent ultrasound-imaging research at the University of Cincinnati has suggested that, whatever the front or top of your tongue is doing with a rhotic, the very back root of it is always tightening your throat.

The ‘r’ is among the last sounds children master… if they ever do

Most rhotics require more effort to say than the average speech sound, and they’re among the last sounds children master… if they ever do. The tongue-tip trill is particularly difficult, so it’s no surprise that speakers might slip over to something slightly easier – economy of effort is an important factor in sound shifts, though we’re also willing to exert effort to make ourselves understood. But ease of saying and hearing aren’t the main reasons for the difference between the ‘r’ sounds you hear as you travel through Europe. Fashion and identity are.

Roll with it

Long ago, Latin speakers said ‘r’ with the tips of their tongues, just as most Italian speakers do now. For a long time, French speakers did too. But in Paris in the late 1600s, some of the smart set started saying a back-of-the-throat ‘r’ – what linguists call ‘uvular’ – perhaps to save effort, perhaps as a fashion. People such as the noted physician Nicolas Andry de Bois-Regard counselled everyone to use the sound, because many people had been converting ‘r’ to other sounds such as ‘l’ or ‘z’ or – gasp – dropping it altogether. And so the uvular ‘r’ started spreading gradually through France and the tongue-tip trill came to be seen as ‘vulgar’ or ‘provincial’.

And then it spread from there, city by city, among the fashionable set, into Germany and the Netherlands and up to Denmark… or so the old story goes. But it’s not quite that simple. There’s evidence that the back-of-the-throat ‘r’ had already shown up in some dialects of German by that time, and not even among the fashionable city set. Nonetheless, the main spread of the uvular ‘r’ through Germany and neighbouring countries did follow the fashionable city folks and travelling merchants. Berlin had it by 1700; it took hold in Copenhagen in the late 1700s and spread from there back through Denmark; it moved into southern Sweden by the late 1800s and stopped. It spread too into Norwegian around Bergen, which has a long history of trade with Germany.

It also moved into the Netherlands, but in any given place in the Netherlands you can hear some speakers who say ‘r’ with the tongue tip, some who say it uvular, and some who say it mid-mouth like Americans, and what’s preferred by young women (who are typically the bellwethers of language change) varies from city to city. Next door in Belgium, though, Flemish (another name for Dutch) avoids the uvular ‘r’. It may have something to do with Belgium also having French speakers: your ‘r’ declares your language group.

Uvular ‘r’ also travelled west. Spanish resisted it (except for a few places), but it took Portuguese by storm. Portuguese, like Spanish, has two kinds of ‘r,’ a heavy one (as in carro) and a light one (as in caro). In the late 1800s, some influential speakers in Portugal’s larger cities started saying the heavy one like the French ‘r’; it may or may not have been by direct influence from France. Within a few decades it had taken over almost completely. It went to the next level in Brazil: depending on where you are and who you’re talking to, you might hear ‘r’ as something like a Dutch ‘ch,’ or a ‘h,’ or – in some contexts – no sound at all. So the Brazilian version of the heavy ‘r’ means that ‘carro’ sounds to us like ‘ca-hoo’, and ‘Rio’ sounds like ‘hee-oo.’

Meanwhile, that other ‘r,’ the light one, stayed more or less the same… until recently. Now some urban speakers in Portugal are starting to say it the American way after vowels. Rural speakers near São Paulo, Brazil, have been doing that for years, but it hasn’t spread because they’re not fashionable – people call their accent fala caipira, ‘hillbilly talk.’

The Scots not only don’t drop the ‘r’, they trill it

We English speakers have insisted on going our own way. By a thousand years ago, English probably had several versions of ‘r’ across the country; historical linguists are still arguing about the details. What we know for sure (thanks to variant spellings) is that by the time of Shakespeare, people in some parts of England were starting to drop it after vowels for economy of effort. But ‘r’-dropping didn’t get the endorsement of the ‘right’ sort of people until the late 1700s, at which point it caught on so briskly that colonials returning to England after the American Revolution expressed surprise at the change.

The ‘right’ sort of people? Well, the ‘upper-right’ sort of people, if you look at a map. R-dropping came to dominate the part of England roughly north and east of the A5 motorway –plus London of course – excepting areas of Lancashire and Northumbria (and stopping at Scotland, where, as in Ireland, there is pride in not sounding English). The Irish don’t drop ‘r’; think of the word ‘Ireland’ – the English pronunciation sounds like ‘island’, whereas the Irish enunciate the ‘r’, so it sounds more like ‘oirrland’. And the Scots not only don’t drop it, they trill it, so ‘Fergus from Aberdeen’ really sounds like ‘Ferrgus from Aberrdeen.’

The southwest English ‘r’ is internationally associated with pirates

The southwest English ‘r’ is internationally associated with pirates, thanks to actor Robert Newton, a native of Dorset, who played Blackbeard and Long John Silver in Disney movies in the 1950s. He’s famous for ‘Arrrr, matey,’ but you’ll hear every ‘r in ‘There be treasure’ too. Then there is the farmer stereotype (‘Get orrf my land’.) Now the ‘r’-dropping is spreading into the southwest as well.

And then there are the Geordies. Already by the 1700s the ‘Northumbrian burr’ – an uvular ‘r’ – was a point of pride. It remained one until the mid-20th Century, when, in the space of about one generation, under the pressure of popular culture, education and fashion, it almost completely disappeared.

The American way

Americans have not been immune to trends, either. Rich and well-educated people in port cities – most notably Boston and New York – soon picked up the British ‘r’-dropping fashion. So did plantation owners in the South, and – from them – others in their area. Poorer people in the South who lived in the mountains away from the plantations did not. Their reward for keeping all their ‘r’s? Their accent is now – as in Brazil – stereotyped as ‘hillbilly.’ But don’t assume a strong mid-mouth ‘r’ always goes with rural; heavy use of the same sound is also a distinctive mark of the Beijing dialect of Mandarin.

‘New York’ has often been rendered in print as ‘New Yawk’

The prestige of ‘r’-dropping lasted a long time in America, but it started slipping after the Civil War, and slid right downhill in the 20th Century. Nancy Elliott, of Southern Oregon University, studied the speech of leading men and women in US films from 1932 through to 1980, and found a steady decline in the rate of ‘r’-dropping, even by the same actors: Fred Astaire went from 80% ‘r’-dropping in the 1930s to 28% in the 1970s; Myrna Loy, from 96% to 7%. At first, more ‘r’-dropping was associated with higher social status and more polite speech; leading men dropped their ‘r’s more when talking to leading ladies and less when getting into fights, and richer people dropped their ‘r’s more than poorer ones. But by the 1960s the prestige associations had switched: a few rich people (villains, for example) still dropped their ‘r’s, but it was increasingly a mark of lower class.

The ‘r’-dropping of New York can be heard in a New Yorker accent saying ‘New York,’ which has often been rendered in print as ‘New Yawk.’ The common joke phrase for the Boston accent is ‘Ya cahn’t pahk ya cah in Hahvad Yahd’ (‘You can’t park your car in Harvard yard’). A well-known American actor who could be counted on to drop his’ r’s was Humphrey Bogart. In “Here’s looking at you, kid” you don’t hear an ‘r’ in “here’s”. In the word ‘world’ sometimes he would say the ‘r’ but sometimes it would sound more like ‘woild.’ A more recent counterpart to Bogart is Harrison Ford, but he always says his r’s – in Star Wars lines like “He’s the brains, sweetheart" or “Never tell me the odds,” you hear the ‘r’ in “sweetheart” and “never,” which Bogart would have dropped (“sweet-haht,” “nevah”).

It’s not ovah, though. The prestige of different ‘r’ sounds in different places is just going to keep shifting. It’s about not just fashion but identity. We could call it the Doctor Who-Are-You of speech sounds.

If you would like to comment on this story or anything else you have seen on BBC Culture, head over to our Facebook page or message us on Twitter.

And if you liked this story, sign up for the weekly bbc.com features newsletter, called “If You Only Read 6 Things This Week”. A handpicked selection of stories from BBC Future, Culture, Capital and Travel, delivered to your inbox every Friday.