Les Nombres Cardinaux

Cardinal numbers are the everyday counting numbers — one, two, three, and so on up. French cardinals are mostly regular and predictable, but there are three specific traps a learner has to clear: the irregular forms from 11 to 16, the vigesimal block from 70 to 99, and the agreement rules on vingt and cent. This page walks through them in order, from zero to the billions, with the agreement, hyphenation, and elision rules at each stage.

0 to 16: the irregular block

The numbers 0 through 16 are individual words that have to be memorized — they don't follow a transparent compositional pattern.

Un / une: the only cardinal with gender

One is the only cardinal that agrees in gender with its noun. Use un with masculine nouns, une with feminine.

This agreement persists in compound numbers that end in -un: vingt-et-un livres (21 books) but vingt-et-une pages (21 pages). This is the only digit that survives this way; deux, trois, etc. are invariable for gender.

The 6, 8, 10 pronunciation shift

Three of the small numbers — six, huit, dix — pronounce their final consonant in three different ways depending on what follows:

This is the single most distinctive pronunciation feature of small French numbers. Huit is the exception that confirms the rule: its -t is always heard except before another consonant.

17 to 69: regular composition

From 17 onward, the system becomes compositional. Numbers 17, 18, 19 are formed dix + digit with hyphens; 20, 30, 40, 50, 60 are the decade words; the numbers between them use either -et un (for the 1s) or a hyphen + digit (for everything else).

Hyphens: traditional vs reformed

Under traditional spelling, hyphens connect consecutive digit-words but et is spelled without hyphens: vingt-deux, vingt-trois, but vingt et un. Under the 1990 reform (spelling/1990-reform), all elements of a compound number are hyphenated: vingt-et-un, trente-et-un. Both spellings are correct; this page uses the reformed form, but you'll see both in the wild.

70 to 99: the vigesimal block (France French)

From 70 to 99, French stops adding new decade words and starts building on top of soixante (60) and quatre-vingts (literally "four-twenties" = 80). This is the famous quirk of French numbers.

Three things to memorize from this block:

1. 71 is soixante-et-onze (with et), but 91 is quatre-vingt-onze (no et). The et only appears once in this band, attached to the -onze of 71.
2. Quatre-vingts takes a final -s when it's the last word (80 itself, quatre-vingts), but loses the -s when followed by another number (quatre-vingt-un, quatre-vingt-deux…). This is the same rule as cent, below.
3. There is no et in any quatre-vingt-X number. Quatre-vingt-un, never quatre-vingt-et-un.

100 and the cent agreement rule

Cent (hundred) follows the same kind of agreement quirk as quatre-vingts: it takes a final -s in the plural, but only when not followed by another number.

The mnemonic: cents and vingts take -s only when they're the very last thing in the number. The instant another digit follows them, the -s vanishes.

1 000 and the mille rule

Mille (thousand) is invariable: it never takes an -s, no matter what follows.

Older French used mil for the thousands of years (l'an mil neuf cent quatre-vingt-dix), but this is now archaic and mille is standard for all uses. The form mil is still occasionally seen in legal documents and dates on certificates.

Million, milliard, billion: numbers that are nouns

This is the third trap. Million (one million), milliard (one billion = 10⁹), and billion (one trillion = 10¹², not the English billion!) are nouns, not number determiners. They behave like kilo or dizaine.

This has two consequences:

1. They take un (or another quantifier) in front: un million, deux millions.
2. They take de before the counted noun, like any quantifier-noun: un million de personnes (a million people).

The false-friend warning: French billion means 10¹² (a million millions), what American English calls a trillion. The American "billion" (10⁹) translates to French milliard. This is the same long-scale vs short-scale split used across continental Europe.

When million and milliard drop de

If a smaller number is sandwiched between million/milliard and the counted noun, the de is dropped:

Numbers as headers, addresses, and identifiers

When numbers function as labels — page numbers, addresses, room numbers, year numbers — they are read as cardinals. Three conventions to know:

• Addresses: J'habite au 12, rue de Rivoli. Read as douze, rue de Rivoli — no preposition, just the number.
• Page numbers: page 47 — read page quarante-sept. Same for chapters, sections.
• Phone numbers in France: grouped in pairs and read as full numbers. 01 42 86 51 33 is read zéro-un, quarante-deux, quatre-vingt-six, cinquante-et-un, trente-trois.

This is genuinely hard to follow at speed if your only experience is digit-by-digit reading. French speakers parse phone numbers in pairs, and that habit shapes how prices, percentages, and statistics get heard.

Source-language comparison

For English speakers learning French cardinals, the surprises are:

• The agreement on un. English one doesn't change; French un/une does, including inside compound numbers (trente-et-une pages).
• The agreement on cent and vingt. Deux cents with -s, but deux cent un without — a rule with no English equivalent.
• The vigesimal 70–99. There is no shortcut. You learn quatre-vingt-dix-sept as a unit and eventually it stops feeling like arithmetic.
• Million and milliard are nouns. English million is a number word (two million people), but French million requires de (deux millions de personnes).
• Billion is a false friend. French un billion = English one trillion.

Common Mistakes

Key takeaways

• The numbers 0 to 16 are individual irregular words.
• 17 to 69 are regular: decade + (et un / hyphen + digit). The et appears only with -un compounds in traditional spelling; the 1990 reform hyphenates everything.
• 70 to 99 are vigesimal in France French: soixante-dix, quatre-vingts, quatre-vingt-dix. Belgium and Switzerland use septante and nonante.
• Un / une agrees in gender, including inside compounds: vingt-et-une pages.
• Cent and vingt take -s when they stand alone as the last element; lose it when followed by another digit.
• Mille is invariable — never takes -s.
• Million, milliard, billion are nouns: they take un in front and de before the counted noun. Billion = trillion (10¹²) in French, not American billion.
• Phone numbers are read in pairs, not digit by digit.