With its “28 by 28” slogan, the Western Balkans' frontrunner is working full steam ahead to become the 28th EU member state by 2028. If it works, Brussels might be faced with a linguistic dilemma.

The Western Balkan language puzzle

Since Montenegrin is the country's official language, Montenegro would very likely request that it become the EU's 25th official language.

Yet it's very similar to another official EU language: Croatian. In fact, Montenegrin, Croatian, Bosnian, and Serbian are all standard language varieties of what was once known as Serbo-Croatian. Following the breakup of Yugoslavia in the 1990s, each successor state named its own variety, making language an important marker for newly independent national identities.

These four languages are more or less understandable to each other. But while a Croat from Zagreb, a Serb from Belgrade, a Bosnian from Sarajevo, and a Montenegrin from Podgorica can sit down together for a coffee without thinking twice about it, the idea of sharing a common language remains politically contentious.

In Croatia, efforts to distinguish from Serbo-Croatian included promoting specifically Croatian vocabulary in place of words perceived as “Serbianisms”.

In Montenegro, too, language remains tricky – the 2023 census shows more citizens declaring Serbian, rather than Montenegrin, as their mother tongue, which schools referred to as “Mother Tongue and Literature” for years to avoid controversy.

In Bosnia, the three official languages (Bosnian, Serbian, and Croatian) require many state institutions to produce three more or less identical versions of legislation and official documents.

Equality vs bureaucracy

For the EU, whether Montenegrin is “different enough” from Croatian to warrant being an official language doesn't matter, as it doesn't classify languages according to linguistic distance (think of Czech and Slovak for example). Instead, official languages are designated by member states and recognised by the Council.

Recognition, however, comes with practical consequences. Before joining the EU, candidate countries translate the entire body of EU law into their official language. Once they become members, EU institutions translate all new legislation, policy documents, and communication.

In terms of cost, some are sceptical about whether it's worth hiring a full set of Montenegrin interpreters and translators when Croatian is so similar.

The EU already spends around €1 billion annually on translation and interpretation across its institutions. Translation alone produced around 2.5 million pages in 2025, more than half of them related to legislation. And even though existing Croatian translations could serve as a basis for Montenegrin versions, adding another official language would inevitably require additional administrative services.

This question has come up before. Other international organisations, like the International Criminal Tribunal for the Former Yugoslavia, opted for more pragmatic solutions. They used “BCS” (Bosnian/Croatian/Serbian) as its working language, and allowed interpreters to work across language standards, regardless of witnesses' and defendants' nationality.

Out of protest, some defendants and witnesses claimed they weren't able to understand languages spoken by interpreters from different ethnic groups, but these claims were dismissed upon the court's consultation with linguists.

But unlike international courts, the EU's language regime is a matter of legal equality and democratic participation. Every official language of EU law carries equal legal value, and citizens have the right to communicate with EU institutions in their own official language.

A new generation

While the gap between language politics and people's practice in real life is already wide, Gen Z might make it wider. A 2026 Democracy Pulse Survey published by Open Society Foundations found that while young people in the Western Balkans continue to strongly identify with their national communities, they are more supportive of regional cooperation than previous generations and recognise the need to move past post-war contexts.

Meanwhile, in 2017, more than 200 linguists, writers, and other public figures from Bosnia and Herzegovina, Croatia, Montenegro, and Serbia signed the Declaration on the Common Language, arguing that the four standards should be considered as one common, polycentric language. Maybe, the Western Balkans' EU accession processes will revive the idea.