Where is French official in Belgium, and why does nobody know how many speak it?
Four linguistic regions, and no language census since 1961: where French is official in Belgium.
In Brussels, about eight in ten young people schooled in Dutch speak French "well or excellently", against fewer than one in ten the other way round, according to the May 2024 language barometer. French is still the city's contact language. How many Belgians speak it? Nobody knows.
Where is French an official language in Belgium?
The answer is in the Constitution, and it is territorial. Article 4 states that Belgium comprises four linguistic regions: the French-speaking region, the Dutch-speaking region, the bilingual region of Brussels-Capital and the German-speaking region. Every commune belongs to one of them. French is official in two: alone in the French-speaking region, alongside Dutch in the nineteen communes of Brussels.
An older article explains the rest. Article 30 provides that "the use of the languages spoken in Belgium is optional; it may be regulated only by law, and only for acts of the public authorities and for judicial matters". The State regulates the language of its own acts, not that of its inhabitants.
If you come from an English-speaking country, this principle may feel foreign, since several of those countries have no official language at national level at all. Two things follow. A Belgian address tells you which language the administration will answer in, never which language your neighbours use with each other. And English, widely known in Brussels, is official in none of the four regions: your paperwork will be in French or in Dutch.
Why does nobody know how many French speakers Belgium has?
Because the State stopped counting. The Walloon Government portal Connaître la Wallonie records that the decision was voted and became "la loi du 24 juillet 1961", the law of 24 July 1961, and that questions about the languages spoken in Belgian communes disappeared from the forms. What follows is unambiguous: no language census has been held in 1961 or since, abandoning a survey created by Adolphe Quételet in 1846.
The reason is on the record. The Harmel Centre wrote that the 1930 census had lost its value in Walloon eyes, that the 1947 one was contested on the Flemish side, and that it had seemed wise to consider abolishing the censuses altogether.
According to a 2009 documentation sheet from the Documentatiecentrum Vlaamse Rand, the last language census was held in 1947, its findings were published only in 1954, and the language border was fixed in 1962. So no figure for the number of French speakers in Belgium rests on an official measurement. They are extrapolations, and they do not agree.
Which languages do you actually hear in Brussels?
One survey measures this, and only for Brussels. The fifth Brussels Language Barometer, carried out by Mathis Saeys for BRIO at the Vrije Universiteit Brussel in May 2024, interviewed 1,627 people and recorded 104 different languages, against 72 in its first edition in 2001, in a region home to more than 180 nationalities.
On French, the sheet is clear: it "reste sans surprise la langue la plus connue à Bruxelles", remains unsurprisingly the best-known language in the city, yet its knowledge "a fortement diminué au cours des deux dernières décennies", has fallen sharply over the past two decades. Meanwhile English is consolidating its place as the second best-known language.
The rest describes a city where almost nobody has only one language:
- half of Brussels residents grew up in a multilingual household;
- a third in a family where neither Dutch nor French was spoken;
- in half of work situations, bilingualism is the norm.
Why is French still the contact language, even outside French-medium schools?
The most striking result is an asymmetry at school. Among young people schooled in Dutch-medium education in Brussels, "environ huit jeunes sur dix", about eight in ten, speak French "bien ou excellent", well or excellently. Among those schooled in French-medium schools, in Brussels or in Wallonia, fewer than ten per cent say they speak Dutch that well. Demand for bilingual schooling is nonetheless strong: 86 % of Brussels residents are in favour of it.
For a learner, the conclusion is practical. In Brussels your French will serve you almost everywhere, including with people whose school language it was not. The reverse is not true, so you do not have to wait until you are bilingual to settle there.
That leaves the question of which French you will hear. People say "septante" and "nonante" where France says "soixante-dix" and "quatre-vingt-dix", a variation our article on French numbers sets out. You will also meet the informal registers and words that belong neither to Paris nor to Montreal. To place this French in the wider picture, French as the fourth most spoken language gives the orders of magnitude, and our level test will tell you where you stand.
What these figures do not tell you
First, they do not tell you what share of Brussels residents knows French. The sheet gives a trend, the "best-known language" and knowledge that has "fallen sharply", but no percentage is printed in its text: those figures appear only in tables published as images. So we quote the trend, not a proportion.
Second, the scope. The barometer covers Brussels and never Wallonia, it was carried out on behalf of the Flemish Government, and its 1,627 respondents are fewer than the 2,500 of 2001. The proportions quoted here are rounded by the source itself.
The sheet even carries an internal tension worth flagging: it describes growing linguistic diversity, while its own counts give 106 languages in 2013, about 100 in 2018 and 104 in 2024. The number of languages is not rising steadily; what is stable is how high it is.
If you are moving to Belgium, three steps are enough. Check which linguistic region your commune belongs to, because that sets the language of the administration. Expect no official statistics on the languages spoken around you, as none have existed since 1961. And judge your linguistic environment by what you hear, not by a percentage read online.
That is the limit of everything above: an article of the Constitution can be checked alone in five minutes, but which variety of French will be spoken to you, and whether your ear follows it, is on no map. At Frenchee, lessons are live with qualified native teachers, one to one or in small groups of three to five students, with no subscription: a teacher can tell you which variety they teach and which one you will hear where you are going to live.
