Why are French numbers so confusing?

Numbers are one of the first things you need to familiarise yourself with when it comes to learning French. But they can also be one of the hardest things to get your head around. True, the first sixty-nine are simple enough, and follow an understandable logic. The six numbers from onze to seize are a confusing exception, but then the teens in English aren’t exactly intuitive, either. It’s when we arrive at seventy that things get a little strange.

You may be aware that the French don’t literally say ‘seventy’; rather they say ‘sixty-ten’. This peculiar form of expression carries on up to 'eighty'—at which point it gets even more perplexing. Instead of saying ‘eighty’, the French say quatre-vingts—literally, 'four twenties'. 'Ninety' is quatre-vingt-dix; 'ninety-nine' is quatre-vingt-dix-neuf.

This complicated system leaves a question on the minds of many newcomers to the French language: why?

Despite appearances, this colouful linguistic abacus wasn’t built this way to deter learners. In fact, the reasons behind this challenging way of counting stretch back thousands of years, to a time when the inhabitants of what is nowadays known as France spoke a language called Gaulish.

Gaulish employs a vigesimal numerical system, meaning that when it comes to counting things, they are grouped in blocks of twenty. This is in contrast to English, for example, where we group things in tens before we begin counting from scratch again: 'ten', 'twenty', 'thirty' and so on. Historians think the explanation behind this discrepancy owes to the fact that the Romans—from whom the English counting system is derived—counted things on their fingers, whereas the Celts counted with their fingers and their toes. Gaulish is a Celtic language—as are Welsh, Gaelic and Breton, which retain the Celtic numerical system to this day (although Welsh has now been reformed to follow the decimal system in most situations).

Of course, French is a romance language, meaning it has a lot in common with the Latin spoken by the Romans. In fact, Roman influence might explain why the first sixty numbers in French adhere to the decimal system. But if we look at a number such as 'eighty-nine', we can see that, although the individual words are completely different in both languages (quatre-vingt-neuf in French, compared with pethrchwochon ná in Gaulish), the numerical logic is exactly the same: ‘four twenties nine’. Gaulish extends this logic towards everything below sixty, too, so that even numbers like 'thirty-three' or 'fifty-nine' are translated as gwochon tridech (twenty-thirteen) and dachwochon nádhech (forty-nineteen), respectively.

Gaulish is no longer spoken. But even today some languages are more confusing than French in the way they count. In Danish, for instance, the word for ninety-two, ​​tooghalvfems, means something like five minus a half, times twenty, plus two—in other words, or numbers, ((5-0.5) x 20) + 2.

Simple, right?

Perhaps unsurprisingly, some French-speaking countries have, like the Welsh, reformed their counting systems to be a bit, well, easier. In Belgium and the French-speaking part of Switzerland, for example, the words septante, huitante and nonante have entered everyday vocabulary. But most other Francophone countries stick to the vigesimal system, so at Learn French with Alexa, we’ll continue saying quatre-vingt-huit, soixante-quatorze, quatre-vingt-dix-sept—and so on…