Every French learner hits the same wall around A1-A2: numbers up to 69 feel completely logical, and then 70 shows up as "soixante-dix" (sixty-ten), 80 as "quatre-vingts" (four-twenties), and 99 becomes the small maths equation "quatre-vingt-dix-neuf" (four-twenty-ten-nine). If your first reaction was "why," you're in good company: even French children have to memorise this the same way you do.
Here's the good news: once you understand the pattern (and the history behind it), these stop feeling random. Let's break it down properly.
Why French numbers do this
The short answer is Celtic and Norman influence. Long before modern French existed, Celtic and Viking (Norman) languages in parts of what is now France counted using a base-20 system (vigesimal), rather than the base-10 (decimal) system Latin used. Traces of that base-20 counting survived in the language, especially around Normandy and Paris, and eventually became the standard taught across all of France, while other French-speaking regions kept the more "logical" Latin-based forms.
That's also why Belgium and Switzerland count differently, and honestly, more sensibly, for 70 and 90 (more on that below). Standard "France French" is, in this one specific corner of the language, the odd one out.
70 to 79: soixante + dix
Seventy through seventy-nine are built as "soixante" (60) plus the teens (10 through 19) added on. So instead of a new word for 70, French just keeps counting up from sixty.
| Number | French | Literally |
|---|---|---|
| 70 | soixante-dix | sixty-ten |
| 71 | soixante et onze | sixty and eleven |
| 72 | soixante-douze | sixty-twelve |
| 75 | soixante-quinze | sixty-fifteen |
| 79 | soixante-dix-neuf | sixty-ten-nine |
Notice 71 is the only one with "et" (and), matching the pattern from 21, 31, 41, 51 and 61 (vingt et un, trente et un...). From 72 onwards, there's no "et," just a hyphen: soixante-douze, soixante-treize, and so on.
80 to 89: quatre-vingts
Eighty is "quatre-vingts": literally "four-twenties" (4 × 20 = 80), the clearest surviving trace of the old base-20 system. From 81 onwards, you drop the -s and add the units directly, with no "et," even for 81.
| Number | French | Literally |
|---|---|---|
| 80 | quatre-vingts | four-twenties |
| 81 | quatre-vingt-un | four-twenty-one (no "et") |
| 85 | quatre-vingt-cinq | four-twenty-five |
| 89 | quatre-vingt-neuf | four-twenty-nine |
Remember the spelling rule: "quatre-vingts" takes an -s only when it's the exact round number with nothing after it. As soon as you add a unit (81, 82...), the -s disappears: quatre-vingt-un, not quatre-vingts-un.
90 to 99: quatre-vingt-dix, the double stack
Ninety combines both quirks at once: "quatre-vingt-dix" is literally "four-twenty-ten" (4 × 20 + 10 = 90). Ninety-nine, the number that breaks every learner's brain the first time they meet it, is "quatre-vingt-dix-neuf": four-twenty-ten-nine (4 × 20 + 10 + 9 = 99).
| Number | French | Literally |
|---|---|---|
| 90 | quatre-vingt-dix | four-twenty-ten |
| 91 | quatre-vingt-onze | four-twenty-eleven |
| 95 | quatre-vingt-quinze | four-twenty-fifteen |
| 99 | quatre-vingt-dix-neuf | four-twenty-ten-nine |
And then, after all that, 100 arrives as a single simple word again: cent. No twenties, no addition, just relief.
Belgium and Switzerland do it differently (and more sensibly)
If you've ever heard a Belgian or Swiss French speaker count, you'll notice they skip the maths entirely. Belgian and Swiss French use septante (70), and Swiss French additionally uses huitante (80, though many Swiss regions still say quatre-vingts), and both use nonante (90). These are the "logical" Latin-pattern words that standard France French abandoned: septante, huitante and nonante simply mean seventy, eighty and ninety, following the same -ante pattern as soixante (sixty).
You won't be marked wrong for not knowing these unless you're specifically dealing with Belgian or Swiss French, but it's worth recognising them if you ever travel there or watch Belgian/Swiss media: someone saying "nonante-cinq" simply means 95.
Tricks to make these actually stick
- Do the maths out loud once. Actually saying "4 × 20 + 10 = 90" to yourself the first few times helps your brain build the decomposition instead of trying to memorise 30 numbers as random noise.
- Drill 70-79 and 90-99 as "continuations," not new numbers. If you already know 10-19 solidly, 70-79 and 90-99 are just soixante/quatre-vingt-dix bolted onto the front. The new content is smaller than it looks.
- Practise phone numbers and prices. French phone numbers are read two digits at a time (like "06 95 84 71 23"), which forces you to produce these numbers constantly in a realistic context, far more useful than counting 1 to 100 in order.
- Say them, don't just read them. These numbers are genuinely a production skill (speaking fluently under time pressure), not a recognition skill. Reading "quatre-vingt-dix-neuf" and understanding it is much easier than producing it instantly when someone asks your age.
Quick practice
Write out these numbers in French.
- 76
- 82
- 91
- 68
- 99
Answers: 1. soixante-seize. 2. quatre-vingt-deux. 3. quatre-vingt-onze. 4. soixante-huit. 5. quatre-vingt-dix-neuf.
This is the stretch of numbers my students dread most, and also the one that clicks fastest once the maths behind it makes sense. Once these numbers feel automatic, the rest of French numbers (hundreds, thousands, dates, prices) are refreshingly straightforward by comparison. It really is just this one stretch, 70 to 99, that requires the extra effort.