If Britain votes to leave the European Union in a referendum next month, it will leave one thing behind: the English language. The French may be reluctant to admit it, but English has become the dominant language for communication between eurocrats who don’t speak the same native tongue, and it will remain so.

A British exit from the EU, or “Brexit,” would leave the bloc’s institutions without their largest and most influential group of native English speakers. That means English in the EU could get problematically weird.

The English of the EU is already strange. “Euro-English” is a thing, and features incorrect usage often introduced by “false friends” from romance languages, like using “‘control’ to mean ‘monitor’ because contrôler has that meaning in French,” as the Economist writes. An official EU report from 2013, ”Misused English Words and Expressions in EU Publications,” addresses dozens of such incorrectly used terms, everything from “actor” to “valorize.”

Consider the entry for “delay,” which has particularly odd usage in the EU:

‘Delay’ is often used in the EU to mean ‘deadline’ or ‘time limit’. In English ‘delay’ always refers to something being late or taking longer than is necessary. You cannot, therefore comply with (or ‘respect’) a delay.

Replacing “deadline” with “delay” is extremely confusing to a native English speaker. Of course, there is nothing fundamentally wrong with a word having multiple meanings, even contradictory ones. (“Oversight,” for example, can mean both keeping careful watch over something and overlooking it.) There is also nothing fundamentally wrong with the emergence of pseudo-languages among non-native speakers, often called “pidgin” languages.

In the context of the EU, though, the stakes are higher.

For one thing, because speakers come from so many linguistic backgrounds, they may each impart different understandings of unconventional English. (The EU has 24 official languages, in addition to numerous regional languages and dialects familiar to officials.) “Delay” as “deadline” may make perfect sense to a eurocrat from Country A but not a colleague from Country B. Miscommunication ensues. Second, the EU is in the business of writing law. The official declarations it makes need to be precise and understandable to the rest of the English-speaking world, even if the reader has no working knowledge of Euro-English.

Even if emotions are raw after Brexit, English is too ubiquitous and practical for the EU to ditch in favor of something else (though France is trying). Without Britain, Ireland will become the primary defender of colloquial English in the EU. Its small contingent will have a hard time persuading larger counterparts like France and Germany to appreciate the subtleties of precise English. It’s also likely that EU members would find it harder to get visas to live in post-Brexit Britain, reducing their opportunities to learn English from native speakers.

In short, without Britain, the EU will become even more inscrutable to outsiders. The UK should be aware of that before the June delay on its referendum.