French numbers are regular up to 69. After that, France counts in twenties.
1 to 16 are unique
un, deux, trois, quatre, cinq, six, sept, huit, neuf, dix, onze, douze, treize, quatorze, quinze, seize. From 17, numbers are built: dix-sept is “ten-seven.”
The tens
vingt (20), trente (30), quarante (40), cinquante (50), soixante (60).
Add a unit with a hyphen (vingt-deux), except for 1, which takes et: vingt et un, trente et un.
70 to 99: counting in twenties
| Number | French | Literally |
|---|---|---|
| 70 | soixante-dix | sixty-ten |
| 71 | soixante et onze | sixty and eleven |
| 80 | quatre-vingts | four twenties |
| 81 | quatre-vingt-un | four-twenty-one |
| 90 | quatre-vingt-dix | four-twenty-ten |
| 99 | quatre-vingt-dix-neuf | four-twenty-ten-nine |
So for 70 to 79, keep counting past ten with soixante: soixante-douze (72), soixante-dix-huit (78). For 90 to 99, do the same with quatre-vingt.
Not everywhere
Belgium and Switzerland say septante (70) and nonante (90), and some parts of Switzerland say huitante (80). In France and Quebec, it's soixante-dix and quatre-vingts.
French uses a space (or a period) to group thousands: 1 000, and a comma for decimals: 2,5.