Numerals

Numerals are particles that express number. There are thirteen numerals in Esperanto:

nul

0

unu

1

du

2

tri

3

kvar

4

kvin

5

ses

6

sep

7

ok

8

naŭ

9

dek

10

cent

100

mil

1000

Other numbers are expressed using combinations of the numerals. Numbers are given using how may thousands, then how many hundreds, then how many tens, and finally, how many ones:

11

dek unu

12

dek du

13

dek tri

14

dek kvar

15

dek kvin

16

dek ses

17

dek sep

18

dek ok

19

dek naŭ

20

dudek

21

dudek unu

22

dudek du

23

dudek tri

30

tridek

40

kvardek

50

kvindek

60

sesdek

70

sepdek

80

okdek

90

naŭdek

100

cent

101

cent unu

110

cent dek

111

cent dek unu

200

ducent

232

ducent tridek du

300

tricent

400

kvarcent

500

kvincent

600

sescent

700

sepcent

800

okcent

900

naŭcent

1000

mil

1001

mil unu

1011

mil dek unu

1111

mil cent dek unu

1234

mil ducent tridek kvar

2000

du mil

2678

du mil sescent sepdek ok

3000

tri mil

4000

kvar mil

5000

kvin mil

6000

ses mil

7000

sep mil

8000

ok mil

9000

naŭ mil

10000

dek mil

11000

dek unu mil

12000

dek du mil

20000

dudek mil

30000

tridek mil

42000

kvardek du mil

999000

naŭcent naŭdek naŭ mil

999999

naŭcent naŭdek naŭ mil naŭcent naŭdek naŭ

Tens and hundreds are written (and pronounced) together, as one word: dudek, tridek, ducent, tricent etc. Everything else should be written as separate words, including thousands.

Tens and hundreds, like other words, are pronounced with an accent on the second to last vowel: dUdek, trIdek, dUcent, trIcent Everything else is pronounced as separate words: dEk dU, dEk trI, cEnt dU, cEnt trI, cEnt dEk dU, dU mIl, trI mIl, dU mIl dEk dU.

If a compound word is created from these basic numerical expressions, for example, substantival number words or adjectival number words, it is possible or obligatory to write the words joined together, with hyphens as necessary.

Nul (zero) was originally a noun: nulo (the name of the number 0). But it has been used for a long time as a numeral without an ending, like in: 0,5 = nul komo kvin (or nulo komo kvin).

In some cases the abbreviated form un' may be used instead of unu.

Use of numerals

Numerals most frequently appear as epithets of nouns. The numbers then don't receive the N or J endings:

Sometimes the noun is omitted (but understood through context):

Nul (zero) normally appears as a numerical epithet only before units of measure:

In other instances, neniu (no, none, no one) is normally used: Mi havas neniun malamikon.

Numerals can also appear independently to fulfill various roles in a sentence. They often act as nouns. They are never used with the J or N endings:

When referring to a number, an ordinal numeral can also be used: la dua numero, la jaro 1990-a, la tricent-tridek-tria ĉambro. But there can be a difference between a number in an order and normal number. For example, kvara (fourth) means that the thing is preceded by three other things, while numero kvar (number four) means that the thing has the number 4 as a sort of "name". In hotels, for example, there are often missing numbers, so that room 100 is not necessarily the hundredth room. And when standing at the end of a street, one may say that house number one is not the first house, but the last.

Special uses of unu

The basic meaning of unu is numerical. This use has already been explained above together with the other numerals. But unu also has some special meanings and uses. Unu can express, among other things, sameness, uniqueness, individuality, and identity:

Unu is also used individually without a noun to follow it. You might say that the noun is understood through context, but in some cases the addition of the noun would be bothersome. In those cases, unu is used as if it were a pronoun"

When an unu is used to mark an individual, or used like a pronoun (or sometimes to show uniqueness), in the description of several individuals, it receives the J ending:

The form unu can't receive the N ending. This is a basic rule that is always valid, whether unu shows number, individuality, or uniqueness: Unu mi renkontis en Londono, alian en Parizo. Never use the form unun. But the form unuj can receive the N-ending, because unuj can never be a pure numeral. It always shows individuality or uniqueness. The form unujn, however, is only very seldom needed: Unujn mi renkontis en Londono, aliajn en Parizo.

The rule that forbids the use of unun but permits unujn is strange from the viewpoint of logic. But it makes sense in view of practical use. In practice, the uses of unu to show number, uniqueness, and individuality are not clearly distinct from one another. There are many cases on the line, and for this reason, the simple rule that unu should never have an N-ending is very practical. It isn't necessary to decide in each and every case whether unu shows number, uniqueness, or individuality. Unuj is, however, only used to show individuality or uniqueness, and therefore there is no problem with using the N-ending with it, if its role in the sentence requires that.

Don't confuse the use of unu to show individuality with the table word iu (some, someone). Unu showing individuality indicates that the speaker knows well which individual he is referring to (though the listener likely does not know). Iu shows that the identity of the individual being discussed is unknown or unclear, or that the identity isn't important.

Iu (some) can often be used instead of unu (one) when it isn't important to show whether an individual is known to the speaker. But unu is more precise. It shows that the speaker already knows the identity.

The adjective certa (certain) sometimes has a meaning similar to the use of unu (one) to show an individual, but certa is stronger. It emphatically shows that something is certainly known to the speaker (but probably not to the listener): certaj okazoj multe da saĝo estas pli malbona, ol se oni ĝin tute ne havus. Hieraŭ vizitis min certa sinjorino Schmidt.

The abundance of uses for unu (one) seems strange to some, especially because textbooks rarely explain it. For that reason, many prefer to use unu in a purely numerical role, preferring use of iu(j) (some), kelka(j) (some, a few), and certa(j) (certain) for other uses. This usage diminishes the richness of the language, because all of these words express different nuances, and all of these nuances are needed.

Unu... la alia

Pronomial use of unu is part of the expression unu... (la) alia (one another), which shows reciprocity. Unu... (la) alia represents an entire abbreviated sentence. Unu normally is the subject in a complete sentence, and (la) alia is an object or has another role other than that of the subject:

The expression unu... (la) alia (one another) may almost always be used without J-endings. When necessary, a J-ending can be added to alia (other) and also to La junaj knabinoj kaj junuloj ĉe la lageto babilas unuj kun la aliaj.unuLa registaroj ĵetas la homojn unujn kontraŭ la aliajn. = La registaroj ĵetas unujn homojn kontraŭ la aliajn homojn. (one) depending on the intended meaning: La junaj knabinoj kaj junuloj ĉe la lageto babilas unuj kun la aliaj. Some of them speak with others of them. Sometimes the form unujn must be used: La registaroj ĵetas la homojn unujn kontraŭ la aliajn. = La registaroj ĵetas unujn homojn kontraŭ la aliajn homojn.

Instead of unu... la alia (one another), the word reciproke (reciprocally) can sometimes be used together with si or another pronoun: La knabino kaj la knabo kisis sin reciproke. = La knabino kaj la knabo kisis unu la alian. Reciproke can also be used together with unu... la alia to emphasize the reciprocity: Vi ne estas reciproke egalaj unu al la alia en la regiono de la spirito. The word inter can also be used like a prefix with a verb, often with si or another pronoun, or the expression inter si (between/among themselves) (inter ni (among us), inter vi (among you)), which always means unu kun la alia (with one another) or similarly: Ili sin interakuzas. = Ili akuzas unu la alian. Ili interparolas. = Ili parolas unu kun la alia. Ili estis tre amikaj inter si. The pronoun si should never be used together with unu... la alia. Don't say: Ili amas sin unu la alian. Say simply: Ili amas unu la alian.

Substantival (noun type) number words

Number words with the suffix ON show fractional numbers:

Numbers higher than 999999 are expressed using substantival number words; that is, numbers in the form of a noun.

miliono

1.000.000 (six zeros)

miliardo

1.000.000.000 (= nine zeros)

biliono

1.000.000.000.000 (= twelve zeros)

triliono

1.000.000.000.000.000.000 (= eighteen zeros)

Some languages, for example English and Russian, give different meanings than Esperanto does to the number words biliono (billion) and triliono (trillion). The Esperanto words should only have the meanings shown above, and no others. There are also higher numbers that are words of this type, but they are very seldom used.

Substantival number words receive the J- and N-endings according to the same rules as other nouns:

Number words in noun form can't directly describe a noun; they are used together with the preposition da:

An ON-word with an O-ending also requires the help of a preposition: Unu tago estas tricent-sesdek-kvinono aŭ tricent-sesdek-sesono de jaro.

Numerals can also become nouns through the addition of an O-ending. In this form, they show a thing with a relationto a number, or a group with that many items. Numbers are always written together before an O-ending. For clarity, a dividing hyphen can be used where there would ordinarily be spaces:

Mixed numbers

When numerals are mixed with number words in noun form to make a number, their differing rules collide. Numerals want to be epithets of the primary word, while noun-type number words are themselves primary words followed by a da expression. Generally, the correct solution is to use da in these cases, because though da used together with numerals is rare, it is in no way wrong.

Adjectival number words

If the A ending is added to a numeral, an adjective is created, showing the number's position in an order, or an ordinal numeral:

Ordinal numerals receive a J-ending and an N-ending just as ordinary adjectives do:

If an A-ending is added to a number with several words, the entire expression can be combined into one word, but the words can also be left separate. In any case, the A-ending is always placed only at the end. If a combined form is used, hyphens can be used to divide the components of the words for clarity. The hyphens should be placed where there are spaces in the original multi-word number:

When an ordinal expression is used alongside an ordinary numeral, the ordinal expression should come first for clarity:

Other number words with the A-ending

ON-words with an A-ending are ordinary adjectives.

Miliona (millionth), miliarda (billionth), etc. are ordinary adjectives, with may theoretically have various meanings according to context. But in practice, they are used almost exclusively to show order in a sequence: Nia miliona kliento ricevos specialan donacon.

The word nula is an ordinary adjective that theoretically may be used with various meanings, according to context, including with an ordinal meaning (nula = zeroth): je la nula horo kaj tridek minutoj. In practice, it is almost only used with the meaning "non-existent, worthless, invalid": Bruo potenca, nula esenco.

Ordinal adjectives from mixed numbers are theoretically possible, but hardly recommended: nia du-milion-unua kliento. Expressions with a numeral should be used instead: nia kliento numero du milionoj unu.

Adverbial number words

Number words with an E-ending have the same meanings as th corresponding adjective forms:

Nuanced use of number words

The prepositions ĝis, inter and po can be used with number words to add nuance in various manners:

In these sentences, the prepositions don't concern the noun that follows at all; they have meaning only for the number. If the number word is removed, the nuance marker must also disappear, because it no longer makes sense.

These prepositions don't mark a role in a sentence when they add nuance to numbers. They are not role markers, but they have an adverbial sort of role: ĉirkaŭ = proksimume; de = minimume; ĝis = maksimume.

Words used to add nuance to number words can be used together with true role markers, which show the role of the whole expression in the sentence:

In these sentences, these particles are only used to add nuance, and are not used as prepositions — with the exception of po (at a rate of). The language's use of po varies. Some use po always as a true preposition, which means that they never use an N-ending together with po, even if that part of the sentence takes the role of an object in the sentence; for example, in Mi donis al ili po dek eŭroj. Other use po only adverbially, and add an N-ending when its role in a sentence requires that, like in Mi donis al ili po dek eŭrojn.. Both uses are considered correct and appropriate for use.

Mathematical expressions

An equal sign (=) can be pronounced as faras (makes) or estas (is) or egalas (al) (equals [to]), more or less according to the preference of the speaker: du kaj du faras kvar, dek minus tri estas sep, du oble du egalas (al) kvar.

Don't use a period (full stop) instead of a comma with decimals. A period is used as a decimal sign in a few countries. But Esperanto, like most countries and languages, uses a comma to mark decimals.

Words for sub-units like grams and cents can sometimes be understood through context in expressions like these: tri kilogramoj (kaj) sepcent, kvar dolaroj (kaj) sepdek kvin. The speaker should be careful to ensure that there is no doubt as to the sub-unit being referenced.

Hours and time

To show the hour, one of the following models should be used. The words horo (hour) and minutoj (minutes) are very frequently left out and understood only through context.

To add more clarity, the expressions en la antaŭtagmezo or antaŭtagmeze (in the morning), and en la posttagmezo or posttagmeze (in the afternoon) may be added. But the 24-hour system may also be used:

Instead of 15 minutoj (15 minutes), kvarono (a quarter), kvaronhoro (a quarter hour) or kvarona horo (quarter hour) may be used. Instead of 30 minutoj (30 minutes), duono (a half), duonhoro (a half hour), or duona horo (a half hour) are often used.

One speaks of the hour using ordinal numbers: tria (third), naŭa (ninth), dek-dua (twelfth), etc. To ask about the time, one therefore uses the question word kiom (how much) + A-finaĵo → (+ final letter A) kioma (how many-eth).

To show when something happens, a role marker must be used, normally je, antaŭ, post, ĝis or ĉirkaŭ:

When referring to hours, the role marker N should ordinarily not be used, because there is a risk of confusing the hour with the date, since it is also shown with ordinal numerals: je la tria = "je la tria horo", la trian = "en la tria tago de la monato".

Dates

The following models should be used to show a date. The words tago (day) and en la jaro (in the year) are very often omitted and understood only through context.

Ordinal numerals can also be used for years, but this usage is becoming more and more uncommon: Estis la lasta de Januaro (en la jaro) mil-okcent-okdek-sepa.

Between the day and the month, de (of) should always be used, because the ordinal number doesn't relate to the month, but to the word tago (day), which is normally left out: la unua de Majo = la unua tago de Majo, la dek-tria de Decembro = la dek-tria tago de Decembro. If the expression la unua Majo (the first of May) were used, it would be referring to the first of several months of May.

To show the date when something happened, is happening, or will happen, a suitable role marker should be used. The N ending is often used for this purpose: