Numbers in Esperanto
Here is the entire Esperanto counting system: nine digit words, three scale words and two joining rules. That is genuinely all of it, and this page will prove the claim by building every number from 0 to 1,000 in front of you. If you have ever fought French's quatre-vingt-dix (four-twenty-ten, meaning 90) or wondered why English needs eleven and twelve before settling into a pattern, Esperanto's numbers are where the language's regularity stops being an abstract selling point and starts paying out.
One to ten
| Number | Esperanto | Say it |
|---|---|---|
| 1 | unu | OO-noo |
| 2 | du | doo |
| 3 | tri | tree |
| 4 | kvar | kvahr |
| 5 | kvin | kveen |
| 6 | ses | sess |
| 7 | sep | sep |
| 8 | ok | ohk |
| 9 | naŭ | now |
| 10 | dek | dek |
Zero, for completeness, is nul as a numeral and nulo as a noun. Esperanto is phonetic and the stress always falls on the second-to-last syllable, so the "say it" column is the last pronunciation help you will need; the alphabet page covers the rest of the letters.
Each digit word links to its page in our Esperanto dictionary, with example sentences from the course and audio in two accents. A corpus favourite from the sep page, useful and self-demonstrating: Semajno havas sep tagojn - a week has seven days.
The two rules that build everything else
Rule one: multiplication joins up. Dudek is du times dek, 20, written as one word. Tricent is three hundred. Rule two: addition stays apart. Dek du is dek plus du, 12, written as two words. Dudek unu is 21.
That is the complete instruction set. Eleven is dek unu, not a special word. Ninety is naŭdek, not four-twenties-and-ten. Forty-seven is kvardek sep, in that order, digits reading left to right the way you write them. The teens, the tens and the hundreds all fall out of two rules you already know from arithmetic:
| Number | Esperanto | Number | Esperanto | |
|---|---|---|---|---|
| 11 | dek unu | 20 | dudek | |
| 12 | dek du | 30 | tridek | |
| 13 | dek tri | 40 | kvardek | |
| 14 | dek kvar | 50 | kvindek | |
| 15 | dek kvin | 60 | sesdek | |
| 16 | dek ses | 70 | sepdek | |
| 17 | dek sep | 80 | okdek | |
| 18 | dek ok | 90 | naŭdek | |
| 19 | dek naŭ | 100 | cent |
From 100 to 1,000
The hundreds multiply exactly as the tens did: ducent (200), tricent (300), up to naŭcent (900), then mil for 1,000. Everything in between is the same two rules applied left to right:
| Number | Esperanto | Built as |
|---|---|---|
| 101 | cent unu | 100 + 1 |
| 123 | cent dudek tri | 100 + (2 x 10) + 3 |
| 250 | ducent kvindek | (2 x 100) + (5 x 10) |
| 499 | kvarcent naŭdek naŭ | (4 x 100) + (9 x 10) + 9 |
| 777 | sepcent sepdek sep | (7 x 100) + (7 x 10) + 7 |
| 999 | naŭcent naŭdek naŭ | (9 x 100) + (9 x 10) + 9 |
| 1,000 | mil | 1,000 |
Beyond that, du mil is 2,000 (usually written as two words, the one typographic wobble in the system) and mil naŭcent okdek sep is 1987. From the mil page's own examples: Mil homoj venis al la kongreso - a thousand people came to the congress; Du mil jaroj pasis - two thousand years passed.
Two small grammar notes and the cardinals are done. Numbers never take the plural -j or the accusative -n: mi vidas tri homojn, and tri stands there untouched while the noun does the agreeing. And a bare number needs no preposition: tri libroj is three books, complete.
Ordinals: add -a
To say first, second, third, add the adjective ending -a: unua, dua, tria, kvara, deka, dek-dua (twelfth), dudek-unua (twenty-first). Since every Esperanto adjective ends in -a, ordinals are just numbers doing an adjective's job, and they agree like any adjective: la unuaj tagoj, the first days.
Ordinals also run the clock. Je la sesa horo is at six o'clock, literally at the sixth hour, and in speech the horo usually stays home: je la sesa. From the ses page: Li venos je la sesa horo - he will come at six o'clock.
Quantities: da, and the fraction machine
Esperanto links a quantity to the stuff being measured with the preposition da: kiom da homoj? (how many people?), multe da tempo (a lot of time), glaso da akvo (a glass of water). Three examples straight from the course corpus:
- Kiom da homoj venis? - How many people came?
- Donu al mi glason da akvo. - Give me a glass of water.
- Mi havas multe da tempo. - I have plenty of time.
Fractions come from the suffix -on-: duono is a half, triono a third, kvarono a quarter, and the pattern keeps going for as long as your denominator does, which is why Esperanto never had to coin a word for seventeenth. Multiples use -obl- (duobla, double) and groups use -op- (duope, in twos). The full tour of the suffixes, with exercises, is in the course's numbers and counting article.
Why this is the system regularity built
Put the three languages side by side at 97:
- French: quatre-vingt-dix-sept - four-twenties-seventeen. A vigesimal fossil, and the reason Belgian and Swiss French quietly use nonante instead.
- English: ninety-seven - respectable, but only after the eleven-twelve-thirteen initiation and the teen reversal that makes seventeen say its digits backwards.
- Esperanto: naŭdek sep - nine-ten seven. What you would design if nobody was allowed to vote on it in the year 800.
This is the general Esperanto experience in miniature, and it is why we point sceptics at the numbers first: the whole system fits in the tables above, was learned in the time it took to read them, and will never spring an exception on you. The rest of the language runs on the same policy; the 16 rules and where the hours actually go make the wider case, and why learn Esperanto makes the honest argument for bothering at all.
Keep counting
Numbers are lesson-sized on purpose. The free 1,000-word course teaches them in context with audio, the basic Esperanto phrases page puts them to work on prices and time, and the Esperanto example sentences page shows 48 graded sentences where the numbers turn up doing their quiet, regular jobs.