“PER un país de tots, l’escola en català,” reads the sign on the Barcelona schoolhouse gate: “For a country for everyone, school in Catalan.” It is a pointed and, to some, ironic symbol of two very different views of language in Spain. Johnson recently travelled through three regions where Catalan has three different statuses. Catalan is spoken informally in southern France, but the region is dominated officially by French. Nearby Andorra, a microstate sitting between Spain and France, is the only officially Catalan-speaking state in the world, and despite mass tourism, public signage tends to be only in Catalan.

It is in Spain that Catalan is the most controversial. Catalan is the official language of the autonomous province of Catalonia. (Nearly identical Valencian is spoken in Valencia.) Speakers of Castilian Spanish tend to make two grumbles regarding Catalan. One, linguistically impossible to justify, is that it isn’t a real language. Spanish-speakers can read Catalan without much difficulty, provided they know a few crucial words that differ quite a bit (Spanish con, “with”, is amb in Catalan, for example, and solo, “only”, is només.) Linguists, however, usually say two varieties are separate languages rather than mere dialects when the speakers of one cannot understand normal full-speed speech in the other. By this standard, Catalan is clearly a language: if you speak Spanish, note how much easier this news item is to read than even the careful, slow speech of Catalonia’s premier is to understand. (Would you happily take a quiz on the contents of his speech?) So Catalan is a real language—and in fact was a literary language before Castilian had risen from obscurity.

The second complaint is that Spain has given Catalan more and more privileges in the semi-autonomous province of Catalonia, and yet the Catalans keep asking for more. Schooling in Catalonia is in Catalan, and pupils from other regions are expected to learn quickly from immersion. Yet Catalan politicians are angling for a vote on full sovereignty. The government in Madrid insists that this is illegal under the constitution, which declares the indivisibility of the nation.

France’s constitution brusquely defines French as the language of the Republic. America’s constitution makes no mention of English. In contrast, Spain’s constitution devotes an entire article to language:

1. Castilian is the official Spanish language of the state. All Spaniards have the duty to know it and the right to use it. 2. The other Spanish languages shall also be official in the respective Autonomous Communities in accordance with their statues. 3. The wealth of the different language modalities of Spain is a cultural heritage which shall be the object of special respect and protection.

The awkwardness of a constitutionally “indivisible” Spain with “autonomous” regions is plain. This explains the different Castilian- and Catalan-based readings of the sign on the school gate. For the Castilian, Spanish is the language of a “country for all”. For the Catalan, linguistic diversity (schools and more in Catalan) is the price of a “country for all”.

Can the paradox be resolved, and if so, how? A look around the European map offers a few clues about running a multilingual country. Switzerland is quatrilingual (German, French, Italian and Romansh) and Belgium trilingual (French, Dutch and German). Luxembourg has two big languages (French and German, nearly all Luxembourgers speak both) and a local Germanic language, Luxembourgish. The situations are different (Switzerland is a stable confederation with medieval roots, Belgium a rickety federation born in 1830, Luxembourg a tiny grand duchy), but they have one thing in common: multilingualism in the country’s native languages is considered a duty of good citizenship—for all.

Spain, meanwhile, privileges one language. Spanish-speakers who move to Catalonia for jobs often resent having to learn Catalan, or having to send their kids to Catalan-medium schools. Catalans in turn resent the resentment of their native tongue. If the union is to continue without trouble, Spain needs not just multilingualism, but enthusiastic multilingualism. Spanish-speakers in Madrid or Malaga should be proud to learn their country’s other languages. For the bold there is Basque (a fascinating language totally unrelated to the Romance group), and for the practical there is Galician (usefully close to Portuguese), while Catalan has the most speakers. Spanish parliament could allow deputies to speak the regional languages. (Last year, three deputies provoked ejection for speaking Catalan.) The Senate already lets senators speak the regional languages, without disaster. Perhaps even Castilian-speaking politicians (following the example of the new king) could throw in a bit of Spain’s other languages into speeches now and again.

As Johnson wrote in the context of Ukraine, national multilingualism is expensive, in budgetary terms and in the trade-off against other priorities—but it is cheaper than the breakup of a country. And the cheapest solution is merely an attitudinal one: all Spaniards should treat Galician, Basque and Catalan not as regional languages. They are languages of Spain, full stop. Treating them as such, and not as a bother, would go a long way.