The incredible language
La nekredebla linguo


un- + cover + desire (discover)


not + believe + able + adjective (incredible)


communicate + tool + singular noun (a means of communication)

Meet Ido, a world language designed for fairer and more logical communication.

Renkontrez Ido, mondo-linguo dizignita por plu yusta e plu logikala komunikado.

What’s Ido?
Quo es Ido?

I·do /ˈēdō/ noun an artificial universal language developed from Esperanto.

Oxford English Dictionary

Ido is the International Language of the Delegation.

an international auxiliary language intended, not to replace … the national idioms

The Delegation for the Adoption of an International Auxiliary Language was founded in 1901, with a program whose essential articles are as follows:

“It is necessary to choose and to spread the use of an international auxiliary language intended, not to replace in the individual life of each people the national idioms, but to serve for written and oral relations between people of different mother tongues.

“An international auxiliary language must, in order to fulfill its role, satisfy the following conditions: (1) It must be capable of being used for the usual relations of social life, for commercial exchanges and for scientific and philosophical relations; (2) It must be of easy acquisition for any person of average elementary education, and especially for people of European civilization; (3) It must not be one of the national languages.”

an International Committee composed of the most competent scholars and linguists in the field … adopted Esperanto with some modifications

From its foundation in 1907, it had received the adhesion of 310 Societies from all countries and the approval of 1,250 members of academies or universities. It then elected an International Committee composed of the most competent scholars and linguists in the field, which, after studying all the old and new projects for a universal language, adopted Esperanto with some modifications. These modifications are intended, while preserving the principles and essential qualities of Dr. Zamenhof’s language, to regularize the application of these principles and to eliminate certain unnecessary complications. Here are the main modifications: (1) Removal of accented letters, permitting to print everywhere texts of this language, preserving the phonetic spelling and often restoring the international spelling; (2) Removal of some grammatical rules that are useless and very annoying for most people, especially for people with primary education (accusative, agreement of the adjective); (3) Regularization of the derivation, the only way to prevent the invasion of idiotisms, and to provide a solid basis for the elaboration of the scientific and technical vocabulary, indispensable for the propagation of the international language in the learned world; (4) Enrichment of the vocabulary by the adoption of new roots carefully chosen according to the principle of maximum internationality.

no unnecessary rules, no exceptions. It truly realizes the ideal formulated by the linguist Jespersen: the easiest language for the greatest number of people.

All the words are, in fact, formed from international roots, common to most European languages, so that they are known in advance by any educated person. It is therefore not a new language to learn: it is the quintessential European language. But it is incomparably easier than any of them, because of its absolute simplicity and regularity: no unnecessary rules, no exceptions. It truly realizes the ideal formulated by the linguist Jespersen: the easiest language for the greatest number of people. It contains (unlike Esperanto) only sounds that are easy for all people to pronounce; therefore, differences in pronunciation are insignificant and not for all troublesome: experience has proven this many times over.

It is therefore the international language, the result of centuries of the evolution and of the experience acquired by the previous systems. It is the only one that can be used in science and accepted by scientists: it is therefore also the only one that has a chance of being adopted one day by governments and introduced into the schools of all countries.

At the end of its 18 sessions at the Collège de France (October 1912), the Committee of the Delegation had appointed a Permanent Commission “to determine the details of the adopted language”. It was as a result of the work of this Commission that the first manuals and dictionaries of the Ido language were published, “in conformity with the decisions taken by the Committee and by the Commission”, as formally attested by a declaration of the said Commission, signed by all its members.

the Uniono por la Linguo internaciona [is] charged with developing and propagating the International Language of the Delegation

The Delegation, having thus completed its mission, regularly dissolved itself on July 31, 1910, after having founded (by virtue of an explicit article of its program) the Uniono por la Linguo internaciona, charged with developing and propagating the International Language of the Delegation.

But what’s the point?

National languages … are hard to learn even to their native speakers.

We need an international language for neutral and effective exchange between nations. National languages such as English are hard to learn even to their native speakers. Their idioms, exceptions and relative lack of coherence make them particularly hard to learn for foreigners. The years required to master those peculiarities could be spared if we used a predictive and logical language such as Ido.

works translated into [Ido] convey their meaning more directly

Ido’s logic makes it so that works translated into the language convey their meaning more directly than in ambiguous languages like English. Just think of all the meanings “light”, “free”, and “back” have in English. In Ido, different words are used for different senses. Also, instead of saying that it’s raining cats and dogs, we use the single word pluv-eg-as, meaning that it’s raining a lot.

word formation multiplies the possibilities yet uses the same word parts

Ido’s system of word formation multiplies the possibilities yet uses the same word parts. New words are logically created without deforming the original shape and meaning of the original word parts, so the meaning of the new words is easily recognized. The word nekredebla uses ne for “not”, kredar for “to believe”, -ebla for “that can be -ed”, -a for an adjective. So it literally means “that cannot be believed”, “incredible”. In just a few seconds your brain has learned word parts which you will be able to reuse for other words. The word nemanjebla, where manjar means to eat, means “inedible”. The word nevidebla, “invisible”. It is like playing with LEGO bricks, and as such is an incredibly fun game of logic!

it is never too late or too early to learn Ido

Ido’s design is beneficial for two secondary reasons: for the young, it is a great way of learning how a language works, and thus helps to become aware of the morphosyntax of one’s own native language and prepares to learn another language—the so-called propaedeutic value of auxiliary languages; for the elderly, it is an excellent mental activity, that is both rewarding for its regularity and demanding for its richness. A growing body of scientific evidence suggests learning a second language in older age can stave off symptoms of mental decline, and we can assume Ido is no exception. As such, it is never too late or too early to learn Ido: people from all ages can benefit from it.

How about the competition?

No single IAL can claim to have yet succeeded in the matter of global adoption.

There is no bad international auxiliary language (IAL) per se, and some of them certainly have more speakers than Ido, but their statistics mean nothing compared to the billions of people who have not learned any of them, do not even know about their existence, and could learn Ido in one year. No single IAL can claim to have yet succeeded in the matter of global adoption. The most spoken constructed language, Esperanto, is less studied on Duolingo than Polish, which is not even an international language. In fact, according to the most optimistic statistics, Esperanto is spoken by two million people, or more or less 0.025% of the world population. English, in comparison, is spoken by 16.5% of all human beings, according to the CIA. That’s a ratio of 660:1. And that’s only the most optimistic statistics: according to a more realistic estimation, there are no more than 180,000 Esperanto speakers. That’s a ratio of more than 7,300:1.

Not only is Ido gender-neutral like English, it is so since the 1910s.

Esperanto normally uses unique diacritics, which still in today’s age are uncomfortable to type on some devices and cause display issues with some fonts. Esperanto possesses an unpredictable system that forms words like “perlabori” (literally to by-work, meaning to earn) instead of Ido’s laborganar (literally work-earn, meaning to earn), and some words like “preĝejo” (literally a praying-place, often meaning a Christian church) have an added meaning that the original word parts did not have (Ido introduced the word kirko for a church). Another example is “vortaro”, which literally means “a group of words” yet is used strictly as “a dictionary” (Ido uses vortolibro for a wordbook and dicionario for a dictionary, whereas vortaro is generally used for a vocabulary). Many longtime users of Esperanto still forget the accusative despite years of practice, whereas Ido simply uses the -n when the object comes before the subject (which for most cases happens mainly in relative clauses). The Esperanto community still has issues with gender (e.g. there is no single official word for “parent”, especially a non-binary person). Not only is Ido gender-neutral like English, it is so since the 1910s. Finally, Ido has phonotactical principles that make pronunciation easier, while Esperanto allows complex consonant clusters that make the language less flowing. Many complain of words such as “eksciti”, pronounced “ex tsee tee”, whereas in Ido it is ecitar, “eh tsee tar”.

Interlingua is designed to be easy for people who already know a Romance language such as Italian or French (or at the very least, English), but it is very difficult for other peoples like the Japanese or Persian speakers. The meaning of its derivations is unpredictable, since it is heavily influenced by the equivalent words in Romance languages. For those unfamiliar with Latin orthography, Interlingua’s spelling is complex since it does not match its pronunciation like in Ido or in Esperanto. Interlingua is in general easy to read, but it is hard to write and speak.

Lingua Franca Nova (Elefen) is a creole-like language and as such deforms words and uses a strict word order that is not intuitive for many nations. Ido’s system has a richer set of sounds without impeding ease of use, and its word ending system allows a much freer word order.

Toki Pona is ambiguous and lacks a rich vocabulary like Ido to express details.

[Ido] is easy to use, regular, logical, predictable, unambiguous, rich and versatile.

Ido has the best design for a world language. It is easy to use, regular, logical, predictable, unambiguous, rich and versatile. You can use it just as well to write down a haiku or to translate the latest scientific article.

Okay, but how does it work?

Also available as a Cheat Sheet.


All letters are pronounced, and always have the same sound: g, s, and t always hard, like in get and set; h aspired, like in home; a = ah; e = a (the letter); i = e (the letter); o = o (the letter); u = oo; c = ts; j like z in azure or like in just; r trilled or like in rap. The rest, including the digraphs ch and sh, are like in English.

Tonic stress is on the last syllable of infinitives (-ar, -ir, -or) and on the before-last syllable of other words (an i or a u followed by a vowel does not count as a syllable, except in one-syllable roots). Ex. ca-díe, méa fílio vólas lernár la línguo internacióna. Elision does not move the stress, but may remove it.

Definite article: la (the). The -a may be elided with an apostrophe: l’, or the article may merge with the previous preposition to form: al, dil, dal, del. The plural le is used only when the -i ending is not used.

Noun: singular with -o, plural with -i.

Adjective and determiner: invariable, with -a. The -a may be elided.

Personal pronouns: me = I, me, myself, tu = you, yourself (intimate singular), vu = you, yourself (singular), il(u) = he, him, el(u) = she, her, ol(u) = it, lu (universal 3rd person singular); ni = we, us, ourselves, vi = you, yourselves (plural), li = they, them, ili = they, them (mascular), eli = they, them (feminine), oli = they, them (neuter).

Possessive determiner-pronouns: mea = my, mine, tua = your(s), vua = your(s), lua (universal 3rd person singular) = his, her(s), its, their(s); nia = our(s), via = your(s), lia = their(s). Pronominal plural with -i replacing -a.

Reflexive pronoun: su = himself, herself, itself, themself, themselves; possessive: sua, plur.: sui. On(u) = one.

Demonstrative determiner-pronouns: ica (this (one), these…), ita (that (one), those…). Pronominal plural: ici (these), iti (those). Indeterminate neuter: ico (this), ito (that). The initial i may be removed.

Relative-interrogative pronouns: sing. qua; plur. qui; neuter quo (what). Pronounce: quah, quee, quough.

When you need to distinguish the gender of a demonstrative or of a relative, you just need to prefix one of the three personal pronouns il-, el-, ol-: il-ca, el-ca, il-ta, el-ta; il-qua, el-qua; etc.

Verb. Invariable in number and person. Word endings of the main tenses:

-ar, present infinitive
-ir, past infinitive
-or, future infinitive
-as, present tense (may be elided, especially es = esas)
-is, past tense
-os, future tense
-anta, present active participle
-inta, past active participle
-onta, future active participle
-ata, present passive participle
-ita, past passive participle
-ota, future passive participle
-us, present conditional
-ez, volitive

The verb to be: esar, is used to form all the passive and the perfect tenses:

Present perfect: me esas aminta = I have loved.
Past perfect: me esis aminta = I had loved.
Future perfect: me esos aminta = I will have loved.
Conditional perfect: me esus aminta = I would have loved.

These perfect tenses may also be formed with the suffix -ab-: me am-ab-as, am-ab-is, am-ab-os, am-ab-us, I have, I had, I will, I would have loved; am-ab-ez, may you have loved; il balde fin-ab-ez, may he soon be done.

In the passive, instead of:
esas amata, (I) am loved, you can say: amesas
esis amata, (I) was loved, you can say: amesis
esos amata, (I) will be loved, you can say: amesos
esus amata, (I) would be loved, you can say: amesus
esez amata, let you be loved, you can say: amesez
esar amata, to be loved, you can say: amesar

Reciprocal verbs: li interamas = li amas l’unu l’altru (l’uni l’altri) = they love each other; li interparolas = li parolas l’unu a l’altru (l’uni a l’altri) = they talk to each other.

To derive adverbs, replace the -a or -o ending with -e or add -e to the end of a preposition: bone = well; nokte = at night; kontree = on the contrary. Add an -e to the end of an adverb of quantity to replace multe (much): sat multe = sate = enough. Because they cannot form adjectives, you may elide the -e of ank-e (also), ankor-e (even now), apen-e (barely), kand-e (when).

Comparatives: la hundo es plu granda kam la kato = the dog is bigger than the cat; la kato pezas min multe kam kavalo = the cat weighs less than a horse; lu es tam inteligenta kam bela = he is as smart as he is beautiful; lu havas tanta amiki quanta enemiki = she has as many friends as enemies; ta domo es la minim chera = that house is the least expensive; ta homi es le maxim richa = those people are the richest.

Numbers: zero = zero, un = one, du = two, tri = three, quar = four, kin = five, sis = six, sep = seven, ok = eight, non = nine, dek = ten, cent = one hundred, mil = one thousand; dozen-o = a dozen, miriad-o = a myriad, milion-o = one million, miliard-o = one thousand million, bilion-o = one million million; etc. Immediate derivations: dek-e-du-o = a dozen (exactly), du-e = in duo. Multiplication with the -a- interfix and addition with the e interfix: mil e non-a-cent e ok-a-dek e quar = nineteen eighty-four (1984). The preposition of quantity is de or nothing: miliono (de) homi = a million people.


InterrogativeDemonstrativeComparativeProximal demonstrativeDefinite
Determinerqua which, what(i)ta that, those(i)ca this, thesela, le (special plural) the
Singularqua who, that, which of them(i)ta that one(i)ca this onelu he, she, it, they
Pluralqui who, that(i)ti those ones(i)ci these onesli they
Neutralquo what(i)to that(i)co thislo it, that
Qualityqual-a what kind oftal-a such (a)tal-a… qual-a… such (a)… as, like… like
Wayqual-e how, liketal-e like so
Quantityquant-a how much, how manytant-a that/so much, that/so manytant-a… quant-a… as much, as many… as
Intensityquant-e how (much)tant-e so (much)
Locative adverbub-e whereib-e therehik-e here
Temporal adverbkand-e whenlor-e thennun now (ho-)
Correlatives of identity
IndefiniteIndiscriminateDistributionWholeNegativeOtherThe two
Determinerul-a someirg-a anysingl-a each, every singleomn-a allnul-a noaltr-a (an)otheramb-a both
Singularul-u someone, one of themirg-u anyone, any of themsingl-u each oneomn-u everyone, all of themnul-u nonealtr-u someone else, another one
Pluralul-i someirg-i anysingl-i eachomn-i allnul-i nonealtr-i othersamb-i both
Neutralul-o somethingirg-o anythingsingl-o every single thingomn-o everythingnul-o nothingaltr-o something else
Wayul-e somehowirg-e anyhowsingl-e singlyomn-e all togethernul-e in no way (ne)altr-e otherwiseamb-e both together
Locative adverbul-loke somewhereirga-loke anywhereomna-loke everywherenul-loke nowherealtra-loke somewhere else
Locative conjunctionul-ube somewhereirg-ube anywhereomn-ube everywherealtr-ube somewhere else where
Temporal adverbul-tempe sometimeirga-tempe anytimesempr-e, omna-tempe alwaysnul-tempe never
Temporal conjunctionirga-kande anytime
Correlatives of selectivity
OneMore than oneSmall quantityUnknown but not greatGreat quantity
Determinerun oneplur-a severalpok-a few, littlekelk-a some, a fewmult-a many, a lot of
Singularun-u onekelk-u some(one)
Pluralun-i someplur-i severalpok-i few, littlekelk-i some, a fewmult-i many
Neutralun-o a unitkelk-o somemult-o a lot
Waysol-e aloneplur-e several at oncepok-e littlekelk-e somewhat, a littlemult-e a lot (tre)
Correlatives of quantity

Word Formation

All words are composed of elements with an invariable shape that always have the same meaning: roots, affixes (prefixes and suffixes), grammatical word endings.

There are 13 grammatical word endings:
-o indicates a singular noun or a neuter pronoun;
-i indicates a plural noun or pronoun;
-u indicates a singular indefinite pronoun;
-a indicates an adjective, determiner, or participle;
-e indicates a derived adverb;
-ar, -ir, -or indicate the infinitive: present, past, future;
-as, -is, -os the indicative: present, past, future;
-us the present conditional;
-ez the imperative.

There’s also the suffixes for the participles, that, like all suffixes, fit between the root and the word ending:
-ant, -int, -ont for the active participle (present, past, future);
-at, -it, -ot for the passive participle (present, past, future).

Immediate derivation

Immediate derivation is done by replacing the ending with another one. Doing so does not add or remove any meaning to the word, but changes its role as a noun, adjective, etc.

From an action verb

dank-ar = to thank
dank-o = thanks
dank-i = several thanks
dank-e = thanks to

From a stative verb

joy-ar = to rejoice
joy-o = joy
joy-i = joys
joy-e = in joy

From a weather verb

pluv-ar = to rain
pluv-o = a rain
pluv-i = rains
pluv-e = in rain

From a noun

kat-o = a cat
kat-i = cats
kat-a = that is a cat or that are cats
kat-e = as a cat

A limited number of nouns that express neither action, state nor weather also derive verbs and vice versa. I call these nouns orfan derivations because no derivation (immediate with endings or mediate with prefixes or suffixes) can provide a direct semantical relationship between the verb and the noun. Because of their internationality, both forms are kept, and immediate derivation is used. Examples of orfan derivations are informo (*info piece of information, informar = to inform), konto (*akunto account, kontar = to count), lumo (light, lumar [*lucar] = to shine), nomo (*namo name, nomar = to name), noto (note, notar [*anotar] = to note), radio (radio or ray, radiar [*rayonar] = to radiate), revuo (a magazine, revuar [*reviuvar] = to review), situo (*sito site, situar = to situate). In all of these cases, context is way sufficient to discern the meaning of the words. Otherwise, the unsanctioned words with asterisks provide alternatives.

From an adjective

bel-a = beautiful
bel-o = a beauty (person or thing)
bel-i = beauties
bel-e = beautifully

Orfan derivations also exist with adjectives and nouns, where the words have a common etymology but no immediate relationship: elastika (*elastica elastic) and elastiko (a rubber band), kronika (chronic) and kroniko (*kroniklo a chronicle), plastika (*plastica plastic) and plastiko (a plastic), publika (*poplika public) and publiko (a public), etc.

From an adverb

morg-e = tomorrow
morg-a = of tomorrow
morg-o = something of tomorrow (e.g. the following day)
morg-i = several things of tomorrow

From a preposition

avan = in front of
avan-e = in front
avan-a = front
avan-o = a front
avan-i = fronts

List of prefixes

ad-, movement, to: ad-portar = bring.
bo-, relative through alliance: bo-patro = father-in-law.
des-, opposite: des-ordino = disorder; des-agreabla = disagreeable; des-infektar = disinfect.
dis-, separation, dissemination: dis-sekar = to dissect.
ex-, former, ex-: ex-oficiro = former officer.
ge-, reunites both sexes: ge-avi = grandparents (grandfather and grandmother).
ho-, in which we are now: ho-yare = this year.
kontre-, against: kontre-dicar = contradict.
mi-, half, semi-: mi-horo = half an hour.
mis-, wrongly: mis-komprenar = misunderstand.
ne-, negation: ne-utila = useless.
par-, completely: par-lernar = learn thoroughly.
para-, that protects against: para-pluvo = umbrella.
pre-, before: pre-dicar = to predict.
retro-, back: retro-cedar = to retrocede.
ri-, repetition: ri-dicar = to resay.
sen-, privation: sen-arma = without weapons.

Scientific and technical prefixes

Used only when the international word uses an equivalent.

anti-, anti-: anti-materio = antimatter.
arki-, arch-: arki-episkopo = archbishop.
auto-, auto-: auto-imuna = autoimmune.
bi-, bi-: bi-ciklo = bicycle.
centi-, centi-: centi-metro = centimeter.
deci-, deci-: deci-litro = deciliter.
deka-, deca-: deka-volt = decavolt.
equi-, equi-: equi-angula = equiangular.
giga-, giga-: giga-bito = gigabit.
hiper-, hyper-: hiper-spaco = hyperspace.
hipo-, hypo-: hipo-tiroidismo = hypothyroidism.
kilo-, kilo-: kilo-gramo = kilogram.
ko-, complement, co-: ko-funciono = cofunction.
mega-, mega-: mega-watt = megawatt.
mikro-, micro-: mikro-ampère = microampere.
mili-, milli-: mili-sekundo = millisecond.
mono-, mono-: mono-silabo = monosyllable.
nano-, nano-: nano-teknologio = nanotechnology.
nona-, nona-: nona-edro = nonahedron.
okta-, octa-: okta-edro = octahedron.
okto-, octo-: okto-silabo = octosyllable.
poli-, poly-: poli-nuklea = polynuclear.
pseudo-, pseudo-: pseudo-cienco = pseudoscience.
quadri-, quadr-: quadri-latero = quadrilateral.
quinqua-, quinqu-, penta-: quinqua-silabo = pentasyllable.
septua-, septua-, septa-: septua-peptido = septapeptide.
tera-, tera-: tera-bito = terabit.
tri-, tri-: tri-angulo = triangle.

List of suffixes

-ach, pejorative (scornful term): popul-ach-o = a rabble.
-ad, frequency, repetition: dans-ad-o = dancing (the art).
-aj, thing made of: lan-aj-o = woolens.
-al, relative to: nacion-al-a = national.
-an, member of: akademi-an-o = an academic.
-ar, collection: hom-ar-o = humanity.
-ari, that receives the action: legac-ari-o = legatee.
-atr, that resembles: sponj-atr-a = spongy.
-e, that has the color, the aspect of: roz-e-a = pink; tigr-e-a = tabby.
-ebl, that one can, that can be: vid-ebl-a = visible.
-ed, content of: bok-ed-o = mouthful; manu-ed-o = handful.
-eg, augmentative: vent-eg-o = hurricane.
-em, inclined to: venj-em-a = vindictive.
-end, that one has to: solv-end-a = that one has to solve.
-er, that takes care of, or usually does: chas-er-o, dans-er-o, fum-er-o, hunter, dancer, smoker; rept-er-o = reptile.
-eri, establishment: buch-eri-o = slaughterhouse; imprim-eri-o = printworks.
-es, state or quality: fort-es-o, strength.
-esk, to become: rich-esk-ar = to get rich; to start doing: dorm-esk-ar = to fall asleep.
-estr, master, chief: komon-estr-o = mayor.
-et, diminutive: mont-et-o = hill.
-ey, local: kaval-ey-o = stable.
-i, domain, jurisdiction: duk-i-o = duchy.
-id, offspring: Sem-id-o = Semite.
-ier, that holds, or characterized by: kandel-ier-o = candlestick; roz-ier-o, rent-ier-o, kuras-ier-o = rosebush, rentier, cuirassier.
-if, to produce: frukt-if-ar = to fructify.
-ig, to render, make: bel-ig-ar = embellish, dorm-ig-ar = to put to sleep.
-ik, sick of: ftizi-ik-o, -a = a phthisic.
-il, instrument: bros-il-o = a brush.
-in, female sex or gender: frat-in-o = sister.
-ind, worthy of: respekt-ind-a = respectable.
-ism, system, doctrine: katolik-ism-o = catholicism, social-ism-o = socialism.
-ist, professional: art-ist-o = artist, dent-ist-o = dentist.
-iv, that can: instrukt-iv-a = instructive.
-ivor, that consumes: temp-ivor-a = time-consuming.
-iz, to provide with: elektr-iz-ar = to electrify.
-oz, full of: por-oz-a = porous.
-ul, male sex or gender: kaval-ul-o = stallion.
-um, suffix of indeterminate meaning (check the dictionary).
-un, unit: grel-un-o = hailstone.
-ur, product: brul-ur-o = a burn.
-uy, container: ink-uy-o = inkwell.
-yun, young (of an animal): han-yun-o = chicken.

Numeral suffixes

-esm, ordinal number: un-esm-a = first, du-esm-a = second.
-im, fractional: tri-im-a = third.
-op, distributive: quar-op-e = four by four.
-opl, multiplicative: du-opl-a = double.


  1. Noun + noun: rel-voyo = railway; dormo-chambro = bedroom (a room to sleep); vorti-libro = wordbook.
  2. Noun + verb: martel-agar = to hammer (act with a hammer); parto-prenar = to participate (take part); mashin-skribar = to type (write with a machine).
  3. Noun + adjective: ciel-blua = sky blue; graco-plena = graceful; lenso-forma = lentiform; ucel-kapa = bird-headed.
  4. Preposition + verb: en-irar = to enter; ek-irar = to exit; ad-portar = to bring (carry to); ek-pulsar = to expel.
  5. Preposition or numeral + adjective or noun: sub-mara = submarine; super-natura = supernatural; inter-naciona = international; du-yara = two year (old); cent-yaro = centenarian; sub-grupo = subgroup; inter-akto = entr’acte.
  6. Determiner or adjective + adjective or adverb: granda-nombra = numerous; blu-okula = blue-eyed; ta-speca = of that kind; sam-tempa = contemporaneous; plur-foye = several times; mea-nome = in my name.

The object of a verb stays the same when adding a compound: me vidas rokajo tra la aquo = me travidas rokajo.

Some (illogical) calques were traditionally accepted in Ido, but they are now progressively replaced: pavimento (a floor) is now preferred to planko-sulo (literally “a plank ground”, from French plancher), potato is now preferred to ter-pomo (literally “an earth apple”, from French pomme de terre and German Erdapfel), and eventually *fokao (a seal) could replace mar-hundo (literally “a sea dog”, from German Seehund).


The article is always in front of the noun, determiner, adjective, or pronoun it accompanies.

Determiners always go at the beginning of the noun phrase.

Adjectives may go in front or behind the noun they modify.

Adverbs may go in front or behind the verb or participle they modify, and in front of the adjective they modify. The adverbs tre and ne always go in front: behind the verb or participle they modify, they are replaced by multe and nule, respectively. The adverbs maxim, min, minim, nur, plu, sat, tam, tro modify the word that follows them; otherwise, maxim-e, min-e, minim-e, nur-e, plu-e, sat-e, tant-e, tro-e is used.

Participles directly follow the auxiliary verb.

Adjectives and participles may initiate adjective and participle phrases, respectively.

Prepositional phrases go after the word they modify.

The normal word order is subject (S), verb (V), object (O).

Syntactical inversion: When the direct object is before the subject of the clause, it is indicated by a final n: la homo, qua-n vu vidis = the man you saw. Like the plural -i, the -n of syntactical inversion is used on a single word.

Interrogative words begin the clause in which they are found.

Dependent clauses are introduced with the conjunction ke: me ne savis, ke tu amoras lu = I didn’t know you love her. The conjunction ke may also be used with prepositions. Me manjas, pro ke me hungras = I eat because I am hungry.


These are partial translations of the Prière sur l’Acropole (1883) written in French by Ernest Renan. The Ido translation (1913, revised in 2022) was done by Louis de Beaufront, the first author of the language. The English translation (2022) was done automatically by DeepL.

Me naskis, deina bluokulo, de barbara genitori, che la bon e vertuoza Cimeriani, qui habitas la bordo di maro senluma, herisata de rokaji, sempre batata da sturmi. Ibe on konocas apene la suno; la flori esas la muski maral, l’algi e la koloroza konki, quin on trovas en la fundo dil gulfeti dezerta. Ibe la nubi semblas sen koloro, ed ipsa la joyo esas kelke trista; ma fonteni de kold aquo ibe fluas ek la rokaji, e l’okuli dil yunini esas quale ta verda fonteni en qui, sur fundi de herbi ondoforma, reflektas su la cielo.

Mea preavi, tam antiqui kam ni povas konocar, esis konsakrit a fora navigado sur mari, quin tua argonauti nultempe konocis. Me audis, dum mea yuneso, la kansoni pri voyaji al polo; me esis bersat en la memoreso dil glaciflotaceri, dil nebuloz mari laktosimila, dil insuli plena de uceli, qui suahore kantadas, e flugeskante omni kune obskurigas la cielo.

I was born, goddess with blue eyes, of barbarian parents, among the good and virtuous Cimmerians who live at the edge of a dark sea, bristling with rocks, always beaten by the storms. One hardly knows the sun there; the flowers are the marine mosses, the algae and the coloured shells which one finds at the bottom of the solitary bays. The clouds seem colorless, and even joy is a little sad; but fountains of cold water come out of the rock, and the eyes of the girls are like those green fountains where, on a background of wavy grass, the sky shines.

 My fathers, as far as we can go back, were dedicated to distant navigations, in seas that your argonauts did not know. I heard, when I was young, the songs of the polar voyages; I was rocked with the memory of the floating ice, of the misty seas similar to milk, of the islands populated with birds which sing at their hours and which, taking their flight all together, darken the sky.

What does it sound like?

Ido has a rich and euphonious sound. Some say it sounds like Italian, others like Spanish, and it greatly varies from one accent to another. There is no bad accent in Ido, as the language belongs to no nation. All that matters is from a diversity of styles comes one single mutual understanding!

Here are a few Ido speakers speaking the language in flesh and blood:

Louis de Beaufront
Brian E. Drake

Andy Feelin
Itziar Gartzia
Andreas Juste
Jean Martignon, Gilles-Philippe Morin, Robert Pontnau, Yorgos Partakanakis, Alex Quaranta, Thomas Schmidt
Gilles-Philippe Morin
Gonçalo Neves
Igor Vinogradov
Steve Walesh
Igor Washirei

What about the vocabulary?

New word roots are usually adopted by following the principle of greatest international use.

Already since the 1910s, Ido has had a rich vocabulary ready for general and specialized usage. The changes applied to the vocabulary since 1914 are subtle and reflect a lot of experience. New word roots are usually adopted by following the principle of greatest international use. Whereas there is no official word for procrastination (temporisar means “to temporize”, which has a different nuance), the international usage of the Latin verb procrastinare (English, French, Italian, Portuguese, Spanish) makes prokrastinar the ideal candidate. When proposing a root in which you have doubts about its international recognition, you may advise readers using the asterisk (*). Ido is the opposite of Orwell’s Newspeak: it always pushes the boundaries of what can be expressed with it.

One of the best dictionaries you can find is the Wikivortaro. On it, you can use the search tool at the top right to find translations and definitions. When translating an English word, search for one word at a time and use the lemma: instead of “cats” type in “cat”; instead of “having” or “had” enter “have”. In the case looking for the definition of an Ido word, enter one word part at a time, using dots for affixes and word endings: for “haveskar” search for “hav”, then “.esk” and finally “.ar”. Or if you’re browsing a root such as “hav”, the first link after “Radiko por:” will usually contain the most complete definition. The more you gain experience with the language, the more you will rely on the definitions written in Ido itself.

an example of Ido’s wonderful reductionism

Here’s another example with lerneyo. At first, when you type in le, the only Ido suggestion is the plural definite article le, which would mean rneyo would be a word. Yet that’s impossible with the language’s phonotactics. Type ler and then the search tool suggests the verb lernar, which means to learn. That means the word is lern + eyo. Searching for ey does not lead to any good results, so it must be a suffix. Enter .ey and you will find the following definition: “denoting the place of, or for, an object or action”. We know that -o means a singular noun. Therefore, lerneyo means a learning place, and you know that without having to search for the whole word in a dictionary. That’s an example of Ido’s wonderful reductionism.

So, does anyone speak it?

about 120 people around the globe speak or write the language actively

The Ido community is alive ever since its creation in 1907. Today, about 120 people around the globe speak or write the language actively. You will probably encounter some of the following people on the internet:

Akerlund, Kerstin (Sweden)
Alcoba, Jaime (Catalonia)
Anderson, Nancy Lee (USA)
Annavarapu, Kiran (USA)
Arkefeldt, Fredrik (Sweden)
Arp, Herbert (Germany)
Bandeira, Eduardo Willians (Brazil)
Barillon, François (France)
Bartlett, Paul (USA)
Basil, Jackson (USA)
Benítez, Leandro (Argentina)
Bento, Miguel (Brazil)
Bergmann, Ray (Australia)
Blakeslee, Jeff (USA)
Botero, Martín Rincón (Germany)
Boz Junior, Geraldo (Brazil)
Carlevaro, Tazio (Switzerland)
Carnaghan, Robert (UK)
Castillo, Rodrigo González (Chile)
Chandler, James (UK)
Chen, Pablo Tay (Peru)
Ciubotaru, George (Moldavia)
Coba, Tea (USA)
Costa, Lucas (Brazil)
Coutiño, Alejandro (Mexico)
Dewidehem, Xavier (France)
Domingo, Alexandre Xavier Casanova (Galicia)
Drake, Brian E. (USA)
Drogi, Gerhild (Germany)
Eising, Doug (Australia)
Estrada, Álvaro Gámez (Mexico)
“Fafnir” (Canada)
Forster, Benjamin “Philóglossos” (Germany)
Gámez, Rafael (Spain)
García, José (Spain)
Gartzia, Itziar (Basque Country)
Gasper, Donald (Hong Kong)
Gensch, Rudolf (Germany)
Givens, Mark (USA)
Glyn, Niclas Ap (Wales)
Gomide, Luiz Borges (Brazil)
Groth, Detlef (Germany)
Haberland, Dorothea (Germany)
Hajduk, Petr (Czech Republic)
Heberlein, Thomas (Germany)
Hernández, José María Rodríguez (Spain)
Hounsounou, François (Benin)
Installé, Patrick (Belgium)
Ito, Takashi (Japan)
Johnsson, William (New Zealand)
Kasper, Frank (Germany)
Kasper, Marion (Germany)
Kennard, David (UK)
Kiefte, Joop (Netherlands)
Kirkham, Deak (UK)
Kle, Martyn (Russia)
Kobayashi, Naoya (Japan)
Kondo, Nadia Rie “Nadi Pedia” (Germany)
Kovac, Shawn (USA)
KV, Nikhil (India)
Landais, Loïc (France)
Lahti, Valtteri (Finland)
Lavallée, Martin (Canada)
Leiteritz, Patrice (Germany)
Levchenko, Rotislav (Russia)
MacLeod, Dave (South Korea)
Madonna, Tiberio (Italy)
Maltsev, Gleb (Lithuania)
Martignon, Jean (France)
Martínez, Antonio (Spain)
Masayha, Seshimo (Japan)
Moisio, Arto (Finland)
Monroy, Meneses (Mexico)
Morin, Gilles-Philippe (Canada)
Möller, Ferdinand (Germany)
Movellán, Pilar Gómez (Spain)
Muelver, Jerry (USA)
Mukilan, Dominic (India)
Muniz, Valter (Brazil)
Neussner, Alfred (Germany)
Neussner, Heidi (Germany)
Neves, Gonçalo (Portugal)
Onland, Jesse (Canada)
Partakanakis, Yorgos (Valencia)
Paul, Sarah (USA)
Philipps, Hermann (Germany)
Pontnau, Robert (France)
Quaranta, Alex (Argentina)
Ramírez, José Cossío (Mexico)
Randehed, Asya (Sweden)
Randehed, Shell H. (Sweden)
Rataichesck, Sady Miguel (Brazil)
Rehnström, Kjell (Sweden)
Richard, Gaël (France)
Rieck, Ricarda (Germany)
Rockett, Allan (UK)
Rogov, Vladimir (Russia)
Sánchez, Bruno B. (Spain)
Santos, João Xavier (Brazil)
Savolainen, Harri (Finland)
Schlemminger, Günter (Germany)
Schmidt, Thomas (Germany)
Schmidtschen, Dieter (Germany)
Scholz, Eberhard (Germany)
Singh, Rachel Wil (USA)
Solís, Carlos (Costa Rica)
Srinivasan, V. R. (India)
Streletsky, Dmitriy (Russia)
Stuifbergen, Hans (Netherlands)
Suprayan, Ingrid (Germany)
Svoboda, Gabriel (Czech Republic)
Takata, Bebson (Japan)
Totten, Peter (Japan)
Trawick, Marcus (USA)
Vergara, José Antonio (Chile)
Vinogradov, Igor (Russia)
Viol, Jürgen (Germany)
Walesch, Steve (Luxembourg)
Washirei, Igor (Japan)
Wendel, Andreas (Germany)
Weston, David G. (UK)
Yegupov, Konstantin (Russia)
Yoshida, Shigeru “Victor Agricola” (Japan)
Zhurayev, Anvarzhon (Estonia)

Here are the main communities where you will find Ido speakers:

one videoconference every Saturday

On Jitsi, there’s one videoconference every Saturday between 15:30 and 18:00 UTC/GMT. Here’s an example!

There are also Ido speakers at other places such as Reddit, Discord, WhatsApp, Twitter, etc.

Now, how can I learn it?

Reading literature is a great way of becoming familiar with the language, and since its creation, Ido has had a big share of translators and original authors. But of course, to get there you will need to start with the basics, and for that reason we recommend you to start with the following books, in order:

Elementary Grammar (coming soon)
Exercaro / Exercises
Unesma Lektolibro (coming soon)
Duesma Lektolibro (coming soon)
Enkhiridion / Enchiridion

Once you will have reached the last book, you will have been exposed to a diverse range of styles. But what’s more, those books are from the early period of the language, and if you get in touch with other members of the community, and read newer books, you will discover newer styles. Ido leaves a lot of freedom, yet offers one single understanding.

Where can I find more content?

Unfortunately, a lot of Ido content is scattered over the web. It is impossible to make an exhaustive list. Nevertheless, some speakers have made public collections, such as:

Internet Archive
La Blua Plumo

Becoming a member of different Ido communities (see above) is a great way to stay tuned for new works.

Even though literature is the best way to explore the language’s vocabulary and grammar, you may stumble upon details where more detailed linguistic material is needed. Here are a few classics to help you engage in deeper learning:

Dr Max Talmey. Exhaustive Text Book of the International Language of the Delegation and Fundamentals of an Artificial International Language. 1919.

Louis Chevreux “Louis de Beaufront”. Kompleta Gramatiko detaloza di la linguo internaciona Ido. 1925.

Marcel Pesch “Marcelo Persiko”. Dicionario de la 10.000 radiki di la linguo universala Ido. Editio princeps 1964.

Further places to check: Paul Bartlett’s webpage and James Chandler’s webpage.

Works published between 1914 and 1930 use a few words that became archaic: patr-o (parent) became genitor-o; patr-ul-o (father) became patr-o; patr-in-o (mother) became matr-o; dub-ar (to doubt) became dubit-ar; delic-o (delight) and auspic-o/auspici-o (auspice) became delici-o and auspici-o; fin-e (at last) became tandem; cirkum-ar (to surround) became cirkond-ar; oficial-a (official) became ofic-al-a. A few later changes: golf-o (gulf) became gulf-o; abstrakt-ar (to abstract) and abstrakt-it-a (abstract) became abstrakt-ig-ar and abstrakt-a. Some details about grammar were also added after 1914, such as -ab-as, ho-, -ivor- (see above), certen-a (certain) alongside ula (a(n), some, certain, (not) any), hodi-e (today) alongside ca-di-e, rules about the comma were abolished, and the elision of -as was introduced.

I have another question. Whom do I ask?

The communities mentioned above are mainly for writing and speaking Ido, so English is generally to avoid. However, using one of the means below, you can ask whatever you want:

Crafted with love by Gilles-Philippe Morin © 2022. The public domain images come from Wikimedia Commons, Pixabay and Pexels. The description and grammar were translated and adapted from Louis de Beaufront’s posthumous 1938 edition of the Vocabulaire Usuel.