English Guide

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The alphabet of Ido is just like in English: a b c d e f g h i j k l m n o p q r s t u v w x y z.


The vowels a e i o u are pronounced approximately as follows:
a as in father;
e between its sound in get and in vein;
i as in marine;
o between its sound in got and in go;
u as in rule.

i becomes like y if in front of a vowel in a plurisyllabic root:
mikro·biologi·o = “mikrobyologyo”;
omna·di·e = “omnadie”.

There are two diphthongs:
au pronounced as ow in owl;
eu pronounced like the vowels e and u run together.

Most consonants are pronounced like in English.

c is always pronounced like ts in bats;
g is always hard as in get and give;
h is always pronounced like in house and hospital;
j is as in French and like the s in pleasure;
r is always sounded or trilled a little as in prize;
s is always sharp as in same and bus (never like z as is the s in comes);
x is as in expert.

Ido uses a few digraphs:
ch is pronounced as in church;
sh is as in ship;
qu is pronounced as in quick;
gu becomes like “gw” if in front of a vowel:
linguo = “lingwo”;
guto = “guto”.


All plurisyllables are stressed on the last syllable but one, except for infinitives.

For example:
libro = li·bro;
simpla = sim·pla;
apud = a·pud;
granda = gran·da;
pardono = par·do·no;
avertas = a·ver·tas;
mashino = ma·shi·no;
trovebla = tro·ve·bla;
linguo = lin·guo;

Infinitives all end with the syllable ·ar which takes the accent:
trovar = tro·var =  to find;
parolar = pa·ro·lar = to speak;
studiar = stu·diar = to study.


The definite article (‘the’ in English) is la as in la ponto (the bridge), and la lagi (the lakes). There is no indefinite article (a or an in English). So navo means ship or a ship according to context.


The vocabulary of Ido is based on that of the six main European languages:

In general, each word is based on as many of these languages as possible, so that many words in Ido are recognizable to people in many countries.

Words of particular types (parts of speech) are in most cases indicated by their endings, and this makes it easy to see the structure of sentences. The root of each word (the part to which the ending is added) is never varied. Some words, such as prepositions, conjunctions and some adverbs do not have special endings.

For example:
en = in;
sur = on;
se = if.


Nouns in the singular end in ·o:
domo = house;
nubo = cloud;
ucelo = bird;
urbo = town.

Nouns in the plural end in ·i:
domi = houses;
libri = books;
flori = flowers;
repasti = meals.


Adjectives end in ·a:
bona = good;
granda = big;
vera = true;
simpla = simple;
saja = wise;
forta = strong.

Comparatives and superlatives are made using the words plu, min, maxim and minim.

For example:
plu forta = stronger;
min forta = less strong.

maxim granda = biggest or largest;
minim saja = least wise.

As in English, adjectives do not change their form. They may be placed either before or after the noun which they qualify.

For example:
reda floro / floro reda = red flower;
granda tablo / tablo granda = large table;
nova libri / libri nova = new books;
granda domi / domi granda = big houses.


Adverbs are mostly derived from adjectives by changing the ending to ·e:
simple = simply;
vere = truly;
bone = well;
rapide = quickly.


Verbs in the infinitive end in ·ar:
kantar = to sing;
skribar = to write;
vidar = to see.

Verbs in the present tense end in ·as:
vidas = see(s);
lernas = learn(s);
flugas = fly/flies.

Verbs in the past tense end in ·is:
vidis = saw;
kantis = sang;
movis = moved.

Verbs in the future tense end in ·os:
vidos = will see;
trovos = will find.

Verbs in the conditional tense end in ·us:
il venus se il povus = he would come if he were able.

Verbs in the imperative mood end in ·ez:
venez! = come!;
irez! = go!;
ni irez = let’s go.

The ending ·anta corresponds to ·ing in English when it means the active present participle:
fluganta uceli = flying birds;
persono skribanta letro = a person writing a letter;
kantanta puerino = a singing girl.

Use of the letters a, i, and o to indicate present, past and future, as in the endings ·as, ·is and ·os is applied also to the active and passive participles.

The ending ·inta forms the active past participle:
fluginta uceli = birds which have flown;
hundo dorminta = a dog which has slept.

Similarly, the ending ·onta produces the active future participle:
stono falonta = a stone that is going to fall;
la puerino kantonta = the girl who is going to sing.

The ending ·ata gives the present passive participle:
letro skribata = a letter (that is) being written;
vorto kantata = a word (being) sung.

The past form has the ending ·ita:
letro skribita = a letter (that has been) written;
lavita vesti = washed clothes;
celita klefo = hidden key;
libro perdita = a lost book.

The future form ends in ·ota:
letro skribota = a letter (that is going) to be written;
la jetota bulo = the ball that is (yet) to be thrown.

Never use “to have” or “to do” (as we do in English) as an auxiliary to form tenses:
Ni esas vidata = we are (being) seen.
Ni esas vidita = we have been seen (literally “we are having-been-seen”).
Ni vidis la kato = we saw the cat, or we have seen the cat.
Ni esas trovota = we are (going) to be found, or we will be found.
Ni esis salvata da nia hundo = we were (being) saved by our dog.
Ni esis (ja) salvita = we had been saved, or we were (already) saved.

An active verb is made passive by using the suffix ·es· between the root and the required verb ending.
For example, vidas means ‘sees’, but videsas means ‘is seen’. So an alternative, shorter way of saying ni esas trovota is ni trovesos = we will be found. Similarly, ol trovesis = it was found.

The suffix ·ab· is used with verbs as an optional substitute for equivalent longer forms ending in ·inta, and preceded by the appropriate form of the verb esar (to be).

This is shown by the following examples:
skribabis = esis skribinta = had written;
vendabos = esos vendinta = will have sold;
vidabas = esas vidinta = has seen (‘is having seen’).

Personal Pronouns

The main personal pronouns are:

me = I, me;
tu = you (intimate singular form, like “thou”);
vu = you (singular);
ilu / il = he, him;
elu / el = she, her;
olu / ol = it;
lu = he, she or it;
ni = we, us;
vi = you (plural of vu);
li = they (plural of lu);
onu / on = one;
su = oneself, himself, herself, itself, themselves.

Note that me means both “I” and “me”, just as in English we do not have separate words for “you” as subject or object. The full forms of il, el, ol are ilu, elu, olu, but the shorter forms are often used. Lu is very useful in situations when we would otherwise need to say il od el (he or she) since it covers both possibilities.

The reflexive pronoun su is used when the object is the same person or thing as the subject:
el vidis su = she saw herself.

Possessive Pronouns

Possessive pronouns are formed by adding the ending ·a to the personal pronouns (to the full form in the case of ilu, elu, olu).

The main ones are:
mea = my, mine;
vua = your, yours (singular);
ilua = his;
elua = her, hers;
olua = its;
lua = his, her, hers, its;
nia = our, ours;
via = your, yours (plural);
lia = their, theirs;
onua = one’s;
sua = one’s own, his own, her own, its own, their own.

For example:
ilu havas elua libro = he has her book;
ol esas certe elua = it is certainly hers;
nia kato e vua hundo esas en mea domo = our cat and your dog are in my house.

Table of Correlatives

The table of correlatives is a very useful reference to translate words such as “where”, “anywhere” and “everywhere”. Printing this table would be a good idea to help you.

What That Some Any Other No Every
Person qua/i
that one
someone else
no one
Thing quo
something else
Place ube
Time kande
at another time
Way quale
that way
in any way
in another way
in no way
in every way
Quality quala
what kind of
a kind of
any kind of
another kind of
no kind of
all kinds of
Quantity quante
how much
that much
irga quanto
however much
altra quanto
another quantity


Any adjective can be turned into an adverb by replacing the final ·a with an ·e. Similarly, from any verb can be obtained a noun (with the noun ending ·o), meaning the corresponding action.

For example:
from vidar (to see) we get vido = (the act of) seeing or sight;
from dankar (to thank) we get danko = thanking or thanks.
from promenar (to walk) we get promeno = walking, or a walk.
from kurar (to run) we get kuro = running, or a run.

The ending ·ing in English has two meanings which must be distinguished. In “the running horse” the word “running” is an adjective and is translated as kuranta (as in la kuranta kavalo). However, in “running is a pleasure” the word “running” is a noun and is translated as kuro as in kuro esas plezuro.

An adjective can be made into a noun by using the ending ·o, the meaning of the noun being someone or something which has that quality.

For example:
from giganta (gigantic) we get giganto = a giant;
from bela (beautiful) we derive belo = a beauty.

Similarly, from parolanta (speaking) we get parolanto = speaker, or someone now speaking, from sequanta (following) we derive sequanto = follower, and from employata (employed) we get employato = employee.

When a noun root is given the ending ·a the resulting adjective has the same meaning. A couple of examples will make this clear. Thus, from the noun papero (paper) the adjective papera describes something which is paper, as in papera chapelo = paper hat. Similarly, from metalo (metal) we get metala (of metal) as in metala taso = metal cup.

More often, adjectives are formed from nouns by adding a suffix. The general-purpose suffix for forming an adjective is ·al·, which is placed between the root and the adjective ending ·a.

For example:
from naturo we get naturala;
from papero we get paperala as in paperala industrio = paper industry.

from lego (law) we derive legala = legal (related to law);
from manuo (hand) we get manuala = manual or by hand.

The suffix ·al· can be used also with verb roots, as in:
edukala = educational (from edukar = to educate).

A verb can be derived from an adjective by use of a suitable suffix, such as ·ig·.

For example:
from mola (soft) we get moligar = to soften.

from intensa (intense) we get intensigar = to intensify;
from varma (warm) we get varmigar = to warm (make something warm).

Compare this with varmeskar = to become warm. Note that a suffix must always be used; we cannot say “varmar” which would be ambiguous (and illogical).

To derive a verb from a noun the appropriate suffix must be used, according to the intended meaning of the verb. In an international language it is essential to make the meaning clear, since different languages give different meanings (and sometimes more than one meaning) to verbs derived from nouns (as, for example, with the English verb “to stone”).

So from the noun martelo (hammer) we use the suffix ·ag· (indicating action) to obtain the verb martelagar = to hammer. This also means that we can go on to derive the word martelago = (the act of) hammering.

Similarly, we cannot turn the noun salo (salt) into a verb just by substituting a verb ending but must include a suffix such as ·iz· (indicating addition of one thing to another) so as to get salizar = to salt (add salt to).

Since an adverb can be made from an adjective, and an adjective from a noun, so we can also make an adverb from a noun.

For example:
from hemo (home) we get heme = at home.

from nokto (night) we can form nokte = at night, or by night.

Derivation of a variety of words from one word root is an important part of the language’s economy and flexibility.

So from the root skrib· (verb skribar = to write) we can derive:
skribo = writing = the act of writing;
skribado = prolonged writing;
skribilo = a writing instrument of any kind;
skribesos = will be written;
skribala = the adjective;
skribita = written;
skriburo = a writing, i.e. something written;
and so on.

Compound Words

Compound words may be formed freely. The last element in the combination is the main one in determining the meaning, while the preceding element only modifies the meaning.

For example:
skrib-tablo = a type of table = a writing table.

vid-punto = viewpoint or point of view;
kristal-klara = crystal-clear;
sub-mara = undersea;
amo-letro = love letter;
te-taso = teacup;
mar-salo = sea salt.

The use of a hyphen is optional but helpful as it makes it easier to see the make-up of compound words; vidpunto and vid-punto are equally valid. The use of the letter o between two nouns which are joined is optional, but advisable where it makes pronunciation easier. So mar-salo and maro-salo are equally valid, as are vid-punto and vido-punto, but letro-buxo is preferable to “letr-buxo”.

It is important to note that nouns cannot be used unaltered as though they were also adjectives, as is often the case in English. So ‘sea salt’ must not be translated by “maro salo”, but must be translated either as one word, mar-salo or maro-salo, or by using the adjective for ‘sea’ (marala) as in marala salo, or by using the word for ‘of’ (di) as in salo di maro. Similarly, ‘love letter’ is letro di amo or amo-letro but not “amo letro”.

Word Order

Word order is similar to that in English, with some exceptions. Adjectives may precede or follow the noun they qualify. Shorter adjectives generally precede the noun, and longer ones generally follow it, but this is not obligatory. Adverbs may be placed anywhere that allows the meaning to be clear.

The subject generally comes before the direct object, but if this order is reversed then the direct object must show this by adding the letter n.

For example:
la hundo chasas la kato (the dog chases the cat), but la hundon chasas la kato (the cat chases the dog);
la viro qua vidas el (the man who sees her), but la viro quan el vidas (the man whom she sees).

The indirect object is always indicated by the use of a preposition.

For example:
el donis la buxo ad il = she gave the box to him.

Never imitate the English sentence “she gave him the box” – where there is no preposition to distinguish the indirect object from the direct one.

A statement is turned into a question not by changing the word order but by starting the sentence with the word ka.

For example:
la treno esis hike = the train was here, but ka la treno esis hike? = was the train here?

Other question words include:
kande = when;
quale = how;
ube = where;
quo = what.

For example:
ube nun esas la treno? / ube la treno esas nun? = where is the train now?

Prefixes & Suffixes

Prefixes and suffixes are very important and give great flexibility to the language. The most useful ones are listed here. A few of these are in fact ordinary words which are therefore also used on their own (such as ne = not), but most are true prefixes or suffixes and can be used only as such, not as separate words.


des· denotes the direct opposite:
desagreabla = disagreeable;
desfacila = difficult;
desavantajo = disadvantage.

dis· denotes separation:
disruptar = to disrupt;
dissemar = to disseminate, to scatter.

ex· ex-, late, retired:
exprezidanto = ex-president;
= ex-officer;
exministro = ex-minister.

mi· half, semi-, demi-:
mihoro = half an hour;
micirklo = semicircle.

mis· denotes wrong action:
mispronuncar = to mispronounce;
misuzo = misuse.

ne· un-, im-, ir-, non-:
neposibla = impossible;
nepopulara = unpopular.

par· used with verbal roots to denote thorough action:
parlektar = to read thoroughly.

pre· pre-, before:
predicar = to predict;
prenomo = first name.

pseudo· pseudo-, false:
pseudoreligioza = pseudo-religious;
pseudocienco = preudoscience.

retro· retro-, backward (used with verbal roots):
retroirar = to go back(ward);
retrotirar = to draw back(ward).

ri· denotes repetition (used with verbal roots):
rifacar = to do over again;
rielektar = to re-elect.

sen· -less, without:
sendenta = toothless;
senavantaja = without advantage.

stif· step-:
stifmatro = stepmother.

vice· vice-, deputy:
viceprezidanto = vice-president.


·ach· gives an unfavourable or disparaging meaning:
hundacho = cur;
infantacho = brat;
domacho = hovel.

·ad· indicates repeated or continued action (added to verbal roots):
frapar = to strike,
frapadar = to strike repeatedly;
frapado = a beating;

parolar = to speak;
parolado = a speech.

·ag· is the root of the word agar (to do, to act) and is used with nouns (especially tools) to form verbs meaning to act with the tool:
martelo = hammer;
martelagar = to hammer.

·aj· (added to adjective or noun) denotes something possessing the quality or made from the material indicated:
belajo = beautiful object;
metalajo = something made of metal.

(Added to a transitive or mixed verb) indicates the object of the action:
sendajo = something sent;
drinkajo = a drink;
dicajo = saying.

(Added to an intransitive verb) means something which acts in the sense of the verb:
brilajo = something shining;
existajo = something existing.

·al· relating to:
nacionala = national;
autunala = autumnal;
naturala = natural;
manuala = manual.

·an· in forming a noun, denotes a member, inhabitant or adherent:
senatano = senator;
klubano = club member;
vilajano = villager.

In forming an adjective (most often with the name of a country), it is used to indicate belonging:
Japoniana = Japanese;
Nederlandana = Dutch.

·ar· denotes a collection or group of objects or beings:
homaro = humanity;
libraro = library, book collection;
hararo = hair;
mutonaro = flock of sheep.

·ari· indicates the object or recipient of an action:
pagario = payee.

·atr· like:
metalatra = metallic, metal-like;
bluatra = bluish.

·e· coloured, having the colour of:
orea = golden;
oranjea = orange(-coloured).

·ebl· -able, -ible:
drinkebla = drinkable;
lektebla = readable;
kredebla = credible.

·ed· -ful, contents of:
pinchedo = a pinch;
glasedo = glass-ful.

·eg· extremely, to a great extent, very large:
pluvegar = to rain very heavily;
pluvego = downpour;
richega = extremely rich;
domego = mansion.

·em· inclined to (added to verbal roots):
laborema = industrious;
atakema = aggressive;
parolema = talkative.

·end· something to be done or which must be done:
pagenda = payable, must be paid;
problemo solvenda = a problem which must be solved.

·er· person, or sometimes animal or thing, which customarily, but not professionally, does something (added to verbal roots):
fumero = smoker;
klimero = climber;
reptero = reptile;
kantero = singer.

·eri· an establishment:
distilerio = distillery;
bakerio = bakery.

·es· denotes a state or quality (as the root of the verb esar, to be):
beleso = beauty;
infanteso = infancy;
maladeso = sickness.

·esk· to begin to, to become:
dormeskar = to fall asleep;
richeskar = to become rich;
sideskar = to sit down (begin sitting).

·esm· ordinal numbers:
unesma = first;
duesma = second.

·estr· chief, head:
urbestro = (town) mayor;
postestro = postmaster;
navestro = (ship’s) captain.

·et· diminutive:
rivereto = brook;
libreto = booklet;
pluvetar = to drizzle;
humideta = a trifle damp.

·ey· place for something or for doing something:
kavaleyo = stable;
laveyo = wash-room;
koqueyo = kitchen.

·id· offspring, descendant:
Izraelido = Israelite.

·ier· (1) characterised by:
kavaliero = cavalier;

(2) a tree or plant bearing the fruit etc indicated:
pomiero = apple tree;

(3) a holder for something:
kandeliero = candlestick.

·if· indicates production or generation of something:
sudorifar = to sweat;
martelifisto = hammer maker.

·ig· to make, render, or transform into:
beligar = to beautify;
petrigar = to petrify;
larjigar = to broaden;
korektigar = to correct.

·il· denotes instrument or means of performing an action (added to verbal roots):
brosilo = brush;
pafilo = gun;
barilo = barrier;
ludilo = plaything, toy.

·im· fraction:
duimo = half;
quarimo = quarter.

·in· female:
spozino = wife;
aktorino = actress;
kavalino = mare.

·ind· deserving to be, worthy of:
respektinda = respectable;
laudinda = praiseworthy.

·ism· denotes a system, doctrine or belief:
socialismo = socialism;
katolikismo = Catholicism;
realismo = realism.

·ist· denotes a person in an occupation or profession:
dentisto = dentist;
kantisto = professional singer;

It also denotes an adherent of a party or doctrine:
elitisto = elitist.

·iv· capable of, that can do something (added to verbal roots):
instruktiva = instructive;
konvinkiva = convincing.

·iz· to provide with or put on:
armizar = to arm;
kronizar = to crown;
butrizar = to (put) butter (on).

·op· so many at a time:
quarope = four together, four at a time.

·opl· multiplying:
duopla = double;
triopla = triple.

·oz· full of, containing:
joyoza = joyful, joyous;
poroza = porous;
kurajoza = courageous.

·ul· male:
spozulo = husband;
katulo = tom-cat.

·ur· result or product of an action (added to verbal roots):
pikturo = picture;
skulturo = sculpture;
aperturo = opening.

·uy· container:
violinuyo = violin case;
sigaruyo = cigar box.

·yun· young of an animal:
bovyuno = calf;
katyuno = kitten;
hundyuno = puppy.


Elision is useful mainly in poetry, of which there is quite a lot in Ido. The final ·a of the adjective may be omitted (e.g., bon instead of bona; nacional instead of nacionala), and the final ·as of the present tense of the verb may be elided (e.g., dank instead of dankas). In ordinary texts, however, the instance most generally found is use of es instead of esas (= am, is, are) since this word is used so often and the shorter form is convenient. (A few other words, such as some pronouns, also have short forms as noted above and in the vocabularies.)


Numbers are formed as shown by the following examples:
un = one;
du = two;
tri = three;
quar = four;
kin = five;
sis = six;
sep = seven
ok = eight;
= nine;
= ten;
dek-e-un = eleven;
dek-e-du = twelve;
dek-e-tri = thirteen;
dek-e-quar = fourteen;
dek-e-non = nineteen;
duadek = twenty;
duadek-e-un = twenty-one;
duadek-e-du = twenty-two;
triadek = thirty;
quaradek-e-kin = forty-five;
cent = hundred;
sepacent-e-duadek-e-sis = seven hundred and twenty-six;
mil = thousand;
miliono = million;
miliardo = thousand million;
biliono = million million.

Note the use of the letter a to link figures which are multiplied together (as in duadek for twenty, i.e. two times ten), and the use of –e- to link numbers which are added to make the required larger number.