Home Introduction Dictionary Translator Learn ESI
Alphabet Verbs Nouns Numbers Extras / Contact

Español Simplificado


Numbers in Spanish are quite trustworthy and stable.


Therefore, there’s no need to revolutionize the numeral system. As always, ESI is aware that almost any language could be simplified almost without limits. It’s like zooming in a fractal image. Nevertheless, the main goal of ESI is not to turn a lively language into an absolutely logical –but artificial- new entity.


In other words, flaws build character.  But too many of them will shut the door to potential new students. In order to operate we need a scalpel; not a hammer. We need a subtle evolution, not a metamorphosis.


ESI knows that there is a thin, blurry border between these two opposed concepts, that’s why we tread lightly when it comes to introducing changes.  Some elements might be very irregular, but they shape the genuine characteristics of the language and getting rid of them would eventually turn it into something else. By contrast, some other irregularities are just like stagnated debris in the shores of a river. They represent small obstacles for those foreigners who want to dive into Spanish, whereas the native speakers themselves wouldn’t actually care if they were removed, or better said, replaced. This is when ESI comes into play.


Numbers from 0 to 10

 In Spanish                                       In ESI                        Others (optional)


0 cero   ------spelling change------     zero


1 uno                                                  uno                                         un?


2 dos                                                   dos                                          bis?


3 tres                                                  tres


4 cuatro*                                            cuatro


5 cinco*    -----spelling change-----  zinco              


6 seis                                                  ses


7 siete                                                sete


8 ocho                                                ocho


9 nueve                                              nove


10 diez*                                              diez                                         deca?

Numbers 6 and 7

Some students find it hard to pronounce “seis” and “siete”. Both of them have diphthongs which look similar but are quite different (ei – ie). ESI simplifies them: “ses” and “sete”. The pronunciation is “flattened”. ESI creates new and practically identical nouns which:


a) sound similar.

b) can be pronounced faster, an important element when it comes to counting.

c) are more regular (ses, sesenta, ses ziento / sete, setenta, sete ziento).

d) don’t bring in new problems of polysemy.

e) in general, they resemble more the English, French, Italian & Portuguese numbers


English                            French                  ESI                  Portuguese   Italian                       

six                                     six                          ses                  seis                  sei      

seven                               sept                        sete                sete                 sette


Number 9

Once again, we get rid of the diphthong in “nueve” and turn it into “nove”. By doing so we achieve similar effects (nove, noventa, nove ziento), exactly the same number as in Portuguese (nove) and Italian (nove), faster & intuitive, easier to pronounce…

*Numbers 4, 5 and 10

These numbers could be changed to make them more regular, but that would create a substantially new or too awkward name as can bee seen analyzing the alternatives: cato, cator, catro, cutro, cuaro, quinco, etc.


Cinco” only turns into “zinco” for spelling reasons (just like “cero” becomes “zero”).


In the case of “diez” (number 10), “deca” (greek etymology) could be considered as an option only in the future (depending on the level of simplification we want to achieve).



- It would be counterproductive to change too many numbers from 0 to 10.

- Two of them (cero and cinco) have changed only due to ESI’s spelling rules.

- Three of them (seis, siete and nueve) have been slightly changed to get rid of their diphthongs. That way we eliminate future derived irregularities.


Numbers from 11 to 19


In Spanish                                        In ESI                                    Others (optional)


11 once                                              onze

12 doce                                              doze

13 trece                                              treze

14 catorce*                                       catorze

15 quince*                                        quinze


16 dieciséis                                      diez y ses                              decasés

17 diecisiete                                    diez y sete                            decasete

18 dieciocho                                    diez y ocho                           decaocho

19 diecinueve                                  diez y nove                           decanove

In this case, we can easily identify two subgroups:


a) Numbers from 11 to 15 end in –ce (-ze in ESI only for orthographical reasons.)


                                         *catorze and quinze remain irregular.


b) Numbers from 16 to 19 are regularized and composed by the formula “10 and x” (in separate words, like the rest of the numbers do).


This way, “diez” doesn’t have to turn into “dieci+number” and no accents are needed          due to the fact that a new single word is created out of three (dieciséis).



- We eliminate 4 irregularities.

Numbers from 20 to 29


In Spanish                                        In ESI                                    Others (optional)


20 veinte                                           vinta                                      binta

21 veintiuno                                    vinta y uno                           binta y un

22 veintidós                                     vinta y dos                            binta y bis

23 veintitrés                                    vinta y tres                           binta y tres

24 veinticuatro                               vinta y cuatro                      binta y cuatro

25 veinticinco                                  vinta y zinco                                    binta y zinco

26 veintiséis                                     vinta y ses                            binta y ses

27 veintisiete                                   vinta y sete                          binta y sete

28 veintiocho                                   vinta y ocho                         binta y ocho

29 veintinueve                                vinta y nove                         binta y nove


Veinte” is an irregularity no matter how we look at it, but it’s hard to normalize.


The 100% logical and regular alternative would be to use something like “dosenta”, but it sounds too alien and artificial. That’s why the only thing we can do is to:


- Get rid of the diphthong (ei) and change it for something faster (i).

- Regularize the ending (turning -NTE into –NTA, just like the rest: 30, 40, 50, 60).

- Divide the single word into 3 (instead of “veintiocho” we have “vinta y ocho”), in correspondence to the rest of the numbers (trenta y ocho, cuarenta y ocho).


Numbers from 30 to 99


30 treinta                                          trenta

31 treinta y uno                               trenta y uno

32 treinta y dos                               trenta y dos

33 treinta y tres                               trenta y tres

34 treinta y cuatro                          trenta y cuatro

35 treinta y cinco                             trenta y zinco

36 treinta y seis                               trenta y ses

37 treinta y siete                              trenta y sete

38 treinta y ocho                             trenta y ocho

39 treinta y nueve                           trenta y nove


- The diphthong in “treinta” becomes simpler: “trenta”. This is in fact something that Spanish-speaking people already does when they’re talking.


40 cuarenta*                                   


50 cincuenta   --spelling change--    zincuenta                   


60 sesenta


70 setenta


80 ochenta


90 noventa


*Cuarenta remains irregular (we always compare them to numbers from 1 to 10).


Numbers from 100 to 999


100 Cien*        --- becomes ---        Ziento


101 Ciento uno                                  Ziento uno


200 Doscientos                                dos ziento


300 Trescientos                               tres ziento


400 Cuatrocientos                          cuatro ziento


500 Quinientos*                              quiniento


600 Seiscientos                                ses ziento


700 Setecientos                               sete ziento


800 Ochocientos                             ocho ziento


900 Novecientos                             nove ziento


One hundred becomes “ziento”, just like in French (cent) or Italian (cento).


The rest of the numbers lose their plural (-s), just like in those aforementioned languages do not have plural for their hundreds (200: “deux cent” in French or “duecento” in Italian. Even “two hundred” in English) and just the same way as “ochenta” or “dos mil” are not expressed as a plural number (ending in –s).


                                         *Quiniento remains irregular.


Numbers from 1000 to one million


1000 Mil                                             mil


2000 Dos mil                                     dos mil


3000 Tres mil                                    tres mil




They remain the same: no plural ending (we don’t say “dos miles”) & separate words.



1000000 un millón*                         millón


2000000 dos millones                      dos millones

3000000 tres millones                     tres millones

*It is no longer necessary to say “un millón”, just the same way as it is not necessary to say “un ziento” (100) or “un mil” (1000) in Spanish. This is in fact something that many Spanish-speaking people already do in their daily lives:


For example, this could be a headline in any newspaper nowadays:


“España tiene millón y medio de parados” (Spain has “million and a half” unemployed people).


*On the other hand, millions do preserve their plural. It would sound too strange to avoid it here. Anyways, this exception could be explained as an emphasis on the magnitude of these ciphers.



Period or comma?

ESI is based on Spanish, so it follows its rules in this case (and most of the European countries’ standards regarding the issue).


Period (punto) is used to divide numbers with many digits into subgroups, for ease of reading. They are delimiters and are written every 3 digits. Period is preferred because its smaller size fits better its purpose: a tiny point that helps reading the number without breaking its continuity.


For example:                   One thousand – mil – 1.000

                                         One million – millón – 1.000.000


Comma (coma) is used for decimals. It is preferred because it’s slightly more noteworthy, its goal is to actually break that “continuity” we mentioned before.


For example:                   0,75

What’s a billion?


ESI might be based on Spanish, but in this case we think the US use of the word makes more sense than the European one.


For instance, a billion in the US represents a thousand million ( That’s quite huge number.


In Europe, it usually represents a million million (

That’s quite huge, huge, huge number.


Obviously, none of these ciphers are too useful in our daily lives, but if there’s one that seems TOO big to be used in any field, it should be the last one. For the sake of efficiency, the word “billion” is applied to the number that seems more likely to be used, which in this case is the smallest one.


To sum up: a billion in ESI is just like a billion in the US.


The same can be said about a trillion. In fact, British English has recently adopted the American figure.

Where to place the currency symbols?

Currency symbols will always be written after the number/price, leaving a space.


It makes sense to apply this rule in a language where everything happens in a logical direction: from left to right.


We say “two thousand dollars”. We don’t say “dollars two thousand”.


                                         Correct     Incorrect


                                         2.000 €    €2,000

                                         99,99 $     $99.99

                                              600 £   £600

                                          1.500 ¥    ¥1,500


When writing a literary text, should I write “3” or “tres”?

· Always write the number with letters when:


                                         a) You mention numbers from 0-15.


                                         Esperé dos horas (instead of “Esperé 2 horas”).

                                         Tenemos todos catorze años (instead of “14 años”)

                                         Hay ocho personas en la fiesta. (instead of “8 personas”).

                                         b) You refer to round numbers.

                                                Quero quiniento hamburgesas (not 500).

                                                Podemos esperar vinta minutos (not 20).

                                                He comprado dos mil bombillas (not 2.000).

· You can directly write the digits:


a)     Obviously, for any mathematical or scientific text.

b)     Any number from 16 to the infinite which is not round.


Habla 16 idiomas.

Posee 143 propiedades.

La poblazión de Francia es de 62.435.539 habitantes.















Diez y ses

Diez y sete

Diez y ocho

Diez y nove











Dos ziento

Tres ziento

Cuatro ziento


Ses ziento

Sete ziento

Ocho ziento

Nove ziento


Dos mil

Tres mil

Cuatro mil

Zinco mil

Ses mil

Sete mil

Ocho mil

Nove mil


Dos millones

Tres millones

Cuatro millones

Zinco millones

Ses  millones

Sete millones

Ocho millones

Nove millones