CROSSING the Oresund bridge from Denmark to Sweden is not merely a matter of a cringe-inducing toll (360 Danish kroner, about $66). Those making the trip, as Johnson did recently on holiday, will suddenly find, like the driver whose favourite radio station starts to go fuzzy at a certain radius from home, a curious shift in languages. A Dane in Sweden can read most of the signs: Välkommen in Sweden means what Velkommen in Denmark means. And the Dane will understand most of the short interactions he has with Swedes. The greeting that both languages write as hej is pronounced like “hi” in Danish and like “hey” in Swedish, and nobody is confused. Thanks is tak on one side of the Oresund and the identically pronounced tack on the other. Even well beyond the pleasantries much of the vocubulary and grammar is similar.

Danes, Swedes and Norwegians (and to a lesser extent, Icelanders and Faroese) like to say that their native tongues are not, relative to each other, “foreign” languages, but rather “neighbour” languages. Some locals and linguists even muse that they may be in fact dialects of a single language. When Scandinavians from different countries meet, they usually attempt to speak their own languages, perhaps with a bit of the rhythm words of the other language mixed in. It’s considered a bit embarrassing to be forced to fall back on English.

But long, winding and complex conversations—in other words, the really good ones—are another matter. For the inexperienced, understanding is far from perfect. It is also asymmetrical: of the three main Scandinavian languages, Danish is the outlier. Centuries of sound change in Denmark have made it an awkward member of the Scandinavian linguistic trio and it is far harder for speakers of the other two to understand. When a Swede asked your columnist “Do you speak Swedish?” the offer of “Danish?” was met with an immediate switch to English. “I can’t really understand the Danes,” he admitted sheepishly.

He could, of course, learn. This article (in Danish) by a professor of Danish at Sweden’s Uppsala University promises that a Swede can learn to understand Danish with just 16 hours of study. And given the nearly twin-city nature of Copenhagen and Malmö today (and lower prices in Sweden), many Danes might want to return the favour. Politiken, a Danish newspaper, published a cheeky mini-phrasebook for Danes heading to the Malmö summer culture festival. (The phrase: “Where did you get your mullet haircut?” is, in Danish, “Where did you get your Swede-neck?” In Swedish, it is “Where did you get your hockey haircut?”)

For all the jokes and misunderstandings, Swedes, Danes and Norwegians have made a good go of the “neighbour languages” business. Most don’t find the time to study each other’s languages in much detail but they do their best anyway, out of a sense of regional solidarity. (Politiken’s phrasebook also includes the Swedish phrase for: “Why are you answering in English? We are Scandinavians, after all.”) It helps that the three countries in question are of roughly equal size and weight: Sweden the biggest and most populous, Norway the richest, Denmark the former colonial heavyweight and current cultural darling. No one lords it over anyone else.

Many other groups could be considered “neighbour languages” on pure linguistic terms, a category that avoids the choice between “foreign languages” and “dialects” while recognising the closeness at hand. But politics often gets in the way. When one language is bigger or more prestigious than the other, the temptation of the bigger one’s speakers to put the smaller language on a distinctly lower pedestal is hard to resist. Johnson’s most recent column, on Catalan and Spanish, triggered hundreds of anguished comments, in a political situation that is currently frustrating just about everybody. Similar frustrations can be found on the South Slavic continuum running across most of the former Yugoslavia, Macedonia and Bulgaria, where nationalist tensions make the similarity (and often near-identity) of the languages a source of friction rather than friendship.

It is easy to forget, but Sweden and Norway almost went to war as recently as 1905 over Norway’s independence. And before that, Denmark had fought Sweden plenty (and ruled Norway from Copenhagen until 1814). But today, the closest thing to fighting-words are, like “Swede-neck”, pretty mild. And the Swedes can respond (as this comic did) that at least they don’t speak, as Danes do, like “Chewbacca with a brain haemorrhage”. Funny stuff, and harmless. If only other language groups could find their inner neighbourliness.