Zamenhof invented the Esperanto word-formation system without bothering to attempt to justify it except by pointing out that ... it works! Couturat, the prime mover behind the Ido conspiracy, felt that this was a major failing in the Esperanto word-formation system -- that it had no supporting theory to justify it. (Though Ido's derivational system did not work as well in practice as Esperanto's, it at least had a theory...)
To answer Couturat, René de Saussure, a member of the Lingva Komitato, began to put together a theoretical basis for the Esperanto word- formation system. His basic theory was expanded by Kálmán Kalocsay, included by Kalocsay and Gaston Waringhien in their Plena Gramatiko de Esperanto, and eventually adopted by the Academy of Esperanto.
The basic idea behind this theory is that every root in Esperanto -- the root, not the word, is the basic unit of Esperanto -- has an inherent grammatical quality. For example, the root ŝton' ("stone") is a noun, the root kur' ("run") is a verb, and the root ruĝ' ("red") is an adjective. Grammatical endings of -O, -I and -A respectively are therefore redundant.
Not all Esperanto speakers were particularly happy with this essential "westernizing" of the word-formation system; some (particularly Kalocsay's countryman István Szerdahélyi) continued to insist that, in fact, roots have no grammatical category whatsoever.
As usual, the truth probably lies somewhere in between. It is possible to categorize Esperanto roots in a number of ways, but one of these is into the categories of object roots (ŝton'), action roots (kur') and attribute roots (ruĝ'). This leaves some questions floating around -- for instance, where do we put roots that describe states, and which might either fall into the attribute category or be linked together, as we often do in the west, with actions? For the nonce, let's leave them hanging loose -- something we could not do with the rather rigid grammatical-category description.
Still, there seems to be a nice correlation between our three categories and the three grammatical categories of the Academy, and we can continue to speak, if we wish, of noun roots, verb roots and adjective roots -- remembering, however, that we are not talking of word categories but simply using a shorthand for how certain roots describe the universe. Don't forget, however, that all of these things can be nouns (that's how we're describing them -- as objects, actions, attributes!), verbs or adjectives -- no grammatical endings are redundant, they are necessary to determine in what grammatical function the root is being used.
So we have O-roots, I-roots and A-roots (for convenience). What role does this play in word formation using affixes?
Most affixes take a certain type of stem (a root or root with affixes) and convert it to another type of stem. The argument has been made, in fact, that certain affixes cannot be attached to certain types of stem because they simply don't take a stem of that grammatical type. But remember from above that the grammatical type is determined not by the content of the stem but by the grammatical ending attached to it. This means that, in fact, every stem is of potentially every grammatical type. Consequently, when you add an affix to a stem it automatically converts that stem to the needed grammatical type just as a grammatical ending would.
Let's try an example. The suffix -EC (a characteristic described by the root) wants to take as input a stem that is an attribute and output something tangible, an object -- in other words A-stem -> O-stem. When we create the word ruĝeco ("redness"), the use is obvious. On the other hand, consider the word ŝtoneco. Here we have input an object word ... or is it? No, we have simply treated the root as an attribute (represented in English by the adjective "stony"), and have created the Esperanto equivalent of "stoniness". Or what about kureco? Here I encounter a problem -- there's no English equivalent that I know of. But the meaning should be obvious -- the characteristic associated with "to run".
With each affix given below I show what kind of input it wants and what kind of output it provides, as A->0 = attribute->object (I = action). X-> means that it will accept any kind of input, while ->X means that it will accept any kind of output; X->X means that it will be transparent to the input.
-ant (I->A): present active participle.
fali = to fall falanta = falling.
-int (I->A): past active participle.
fali = to fall falinta = fallen.
-ont (I->A): future active participle.
fali = to fall falonta = going to fall.
-at (I->A): present passive participle.
manĝi = to eat manĝata = being eaten.
-it (I->A): past passive participle.
manĝi = to eat manĝita = (having been) eaten.
-ot (I->A): future passive participle.
manĝi = to eat, manĝota = going to be eaten.
In English, the past participle indicates only something that has
already occurred; it may be active ("fallen") or passive ("eaten")
depending on the category of the verb; in the latter case, it may
be treated as active (in compounds) by preceding it with the
helping verb "to have" instead of "to be." In Esperanto, there are
separate active and passive participles (though the latter exist
only for transitive verbs).
EXAMPLES
La arbo estis falinta = The tree was fallen (had fallen).
La arbo estis falanta = The tree was falling.
La arbo estis falonta = the tree was going to fall.
La arbo estas falinta = The tree is (has) fallen.
La arbo estas falanta = The tree is falling.
La arbo estas falonta = The tree is going to fall.
La arbo estos falinta = The tree will have fallen.
La arbo estos falanta = The tree will be falling.
La arbo estos falonta = The tree will be going to fall.
La viando estis manĝita = The meat was (had been) eaten.
La viando estis manĝata = The meat was (being) eaten.
La viando estis manĝota = the meat was going to be eaten.
La viando estas manĝita = The meat is (has been) eaten.
La viando estas manĝata = The meat is being eaten.
La viando estas manĝota = The meat is going to be eaten.
La viando estos manĝita = The meat will have been eaten.
La viando estos manĝata = The meat will be being eaten.
La viando estos manĝota = The meat will be going to be eaten.
Please watch out for one annoying idiosyncracy of the participial affixes. When
used with adjective, adverb and (occasionally) verb endings, they describe a
situation; when used with the noun ending, they describe a person.
but
-ad (I->O): shows an action or process defined by the root.
marteli = to hammer, martelado = hammering
boji = to bark (like a dog) bojado = barking
ada = continual, ongoing
-aĵ (A->O): shows a concrete, tangible manifestation of the root.
riĉa = rich, riĉaĵoj = riches
havi = to have havaĵoj = possessions
aĵo = a thing
-ec (A->O): shows a quality or characteristic defined by the root.
riĉa = rich, riĉeco = richness
blua = blue blueco = blue (of something)
eco = a characteristic, quality
The noun formed by simply changing an adjective -a to a noun -o
ending is slightly different from that formed by inserting the
suffix -ec; the former refers to an abstraction, the latter to a
quality associated with something. ruĝa = red, ruĝo = (the
color) red, ruĝeco = redness, e.g. of paint.
-ul (A->O): shows a person characterized by the root.
riĉa = rich, riĉulo = a rich person
bona = good bonulo = a good person
ulo = a guy, dude
-an (O->O): member, adherent, participant of the root.
komitato = committee komitatano = a committee-member
Budho = the Buddha budhano = a Buddhist
ano = a member
-ar (O->O): a collection of things defined by the root.
arbo = tree arbaro = a forest
ŝafo = a sheep ŝafaro = a flock of sheep
aro = a bunch, group, array
-ej(O->O): a place intended for the thing(s) or action(s) defined by the root.
kuiri = to cook kuirejo = a kitchen
preĝi = to pray preĝejo = a church
ejo = a place
-er (O->O): the smallest part or element of a collective defined by the root.
sablo = sand sablero = a grain of sand
neĝo = snow neĝero = a snowflake
ero = a unit
-estr (O->O): the boss of whatever is defined by the root.
komitato = committee komitatestro = chairmain of the
committee
urbo = town urbestro = mayor
estro = a boss
-id (O->O): the offspring of the creature defined in the root.
kato = cat katido = akitten
arbo = tree arbido = a sapling
ido = an offspring
This suffix is often used in a very metaphorical fashion. For
instance, Israelites in Esperanto is Izraelidoj; and it is also
used to show the salt produced by a halogenic acid (e.g. klorido).
-il (I->O): a tool for doing whatever is defined by the root.
komputi = to compute komputilo = a computer
tranĉi = to cut tranĉilo = a knife
ilo = a tool
-in (O->O): the specifically female version of whatever is defined by the root.
filo = son filino = daughter
viro = man virino = woman
ino = a woman, female
These days this suffix is used: (1) with the words viro and knabo;
(2) with honorifics; (3) with family relationships; (4) with
animals (see also vir- below). It is rarely used with professional
titles, though it has been in the past.
-ing (O->O): a holder or sheath for an object defined by the root.
kandelo = candle kandelingo = candle-holder
cigaro = cigar cigaringo = cigar-holder
ingo = a holder
-ism (O->O): a doctrine, movement, system, etc., for the idea defined by the
root.
Budho = Buddha budhismo = Buddhism
Markso = Karl Marx marksismo = Marxism
isma = having to do with doctrine
-ist (I->O): an individual professionally or avocationally occupied with the
idea or activity defined by the root.
ĵurnalo = newspaper ĵurnalisto = newspaperman,
reporter
lingvo = language lingvisto = a linguist
isto = a professional
There is an unfortunate tendency to use -ist where -an should be
used, probably because -ist has this additional meaning in many
Western languages; probably the most egregious such misuse is
*esperantisto instead of esperantano for a speaker of Esperanto.
Similarly, we have *marksisto for marksano (Marxist), *budhisto
instead of budhano (Buddhist), etc. Fortunately, the word for a
follower of Christ in English (with cognates in other languages
such as French) is Christian; so no one has ever had any trouble
saying kristano instead of *krististo.
-uj (O->O): a container for objects described by the root.
salo = salt salujo = salt-shaker
mono = money monujo = a purse
ujo = a container
Traditionally, -uj has been used to form the names of countries
occupied completely or mainly by a single ethnic group: anglo =
Englishman, Anglujo = England. Recently the unofficial or pseudo
suffix -i has been replacing -uj in common parlance. There is a
good discussion of the question of country names in Teach Yourself
Esperanto, as well as in the Plena Analiza Gramatiko (the latter
is, of course, more complete).
*-i (O->O): an unofficial suffix with four different uses:
(1) to form the name of a country from a capitol or river of the same
name.
Meksiko = Mexico City Meksikio = Mexico
Alĝero = Algiers Alĝerio = Algeria
(2) to form the name of a country from its inhabitants. See note with
-uj.
(3) to form the name of a science, etc., from its practitioner.
astronomo = astronomer astronomio = astronomy
toksikologo = toxicologist toksikologio = toxicology
(4) to form the name of a flower from that of its inventor or the
person to whom it was dedicated.
fuksio = fuchsia, from Fuchs
*-ik (O->O): an unofficial suffix to form the name of a science, etc., from its
practitioner.
poeto = poet poetiko = poetics
lingvo = language lingviko = linguistics
This is identical, and interchangeable, with use (3) of -i.
-ik is also used to show the higher of two valences with which a metal can combine. In this it contrasts with one use of -oz.
*-it (O->O): an unofficial suffix to describe an inflamation of the organ
described by the root.
laringo = larynx laringito = laryngitis
hepato = liver hepatito = hepatitis
-it and -at are used as special chemical suffixes to show salts
produced by non-halogenic acids (see also -id).
-ebl (I->A): suitable for having whatever is described by the root done to it.
legi = to read legebla = readable, legible
fari = to do farebla = doable
ebla = possible
ebli = to be possible
-ebl (able to be done) should not be confused with -iv (able to
do), which is essentially a synonym for the root pov'. Many
English-speaking beginners tend to make this mistake and
substitute the verb eblas (is possible) for povas (is able to).
-em (I->A): having an inclination or tendency towards whatever is described by
the root.
ami = to love amema = loving
labori = to work laborema = industrious
emi = to have a tendency to
-end (I->A): must have whatever is described by the root done to it.
fari = to do farenda = must be done
sendi = to send sendenda = must be sent
enda = mandatory
-ind (I->A): worth having whatever is described by the root done to it.
ami = to love aminda = loveable
fari = to do farinda = worth doing
indi = to be worthwhile
*-al (O->A): used to create the adjective form of a noun formed directly from
an adjective.
varma = hot varmo = heat varmala = thermal
ruĝa = red ruĝo = red (color) ruĝala = having to do with
the color red
*-esk (O->A): similar to, or in the manner of, whatever is described by the
root.
japano = a Japanese japaneska = Japanesque
statuo = a statue statueska = statuesque
*-iv (I->A): capable of doing whatever is described by the root.
pagi = to pay pagiva = solvent
fari = to do fariva = able to do
See the note with the description of -ebl.
*-oid (O->A): with the form of whatever is described by the root.
homo = human being homoida = humanoid
urso = a bear ursoida = ursoid
*-oz (O->A): used with noun roots to show the presence of a large quantity of
whatever is described by the root.
poro = pore poroza = porous
sablo = sand sabloza = full of sand
-oz is also used in a medical sense for several different types of
pathology, where it usually corresponds to the suffix osis in
English medical terminology. It need not, however, be used only
with Greek roots; see the Esperanto horzonozo, jet lag. In
chemistry it is used in contrast with -ik to show the lower of two
valences with which a metal can combine.
-ig (A->I): to cause something to be in the state described by the root.
ruĝa = red ruĝigi = to (cause to) turn red
fari = to do (something) farigi = to have (something) done
igi = to cause to
-iĝ (A->I): to become in the state described by the root.
ruĝa = red ruĝiĝi = to become red
fari = to do fariĝi = to become (done)
iĝi = to become
-ig and -iĝ are probably the two most important affixes in
Esperanto. It behooves you, as a student, to devote a lot of time
to making sure that you understand their uses perfectly.
*-iz (O->I): to apply something (physically or metaphorically) to an object.
plumo = feather plumizi = to fletch
stano = tin stanizi = to tin (as in soldering)
-art (I->O): the art of whatever is described by the root.
kuiri = to cook kuirarto = cuisine
navigi = to navigate navigarto = navigation (the art)
-am (O->A): loving whatever is described by the root.
gasto = guest gastama = hospitable
mono = money monama = avaricious
-hav (O->A): possessing whatever is described by the root.
flugilo = wing flugilhava = winged
oro = gold orhava = possessing gold
-plen (O->A): full of whatever is described by the root.
oro = gold orplena = full of gold.
humila = humble humilplena = full of humility
See *-oz.
-pov (I->A): capable of whatever is described by the root.
esprimi = to express esprimpova = expressive
pagi = to pay pagipova = solvent
This is essentially the same as *-iv.
-riĉ (O->A): rich with whatever is described by the root.
karbo = coal karbriĉa = rich in coal
grasa = fat grasriĉa = fatty
See *-oz.
-ŝajn (A->A): seeming to be whatever is described by the root.
vera = true verŝajne = apparently
blua = blue bluŝajna = blue-seeming
-aspekt (O->A): having the appearance of whatever is described by the root.
reĝo = king reĝaspekta = with the seeming
of a king, kingly
hundo = large hundaspekta = looking like a dog
See *-oid.
-simil (O->A): being similar to whatever is described by the root.
floro = flower florsimila = like a flower
ŝtono = stone ŝtonsimila = like a stone
See *-esk.
-manier (O->A): with the manner of whatever is described by the root.
besto = animal bestmaniera = with the manner of
an animal
hundo = dog hundmaniera = dog-like
See *-esk.
Kalocsay and Waringhien also point out, under this rubric, the interesting tendency of the pseudosuffixes -ci, -aci and -ici in nouns taken by Zamenhof from Latin's third declension to disappear in favor of simpler, more purely Esperanto verb forms as time goes on. For instance, Zamenhof's navigacio = navigation has largely yielded to navigi = to navigate, from which we get the purely Esperanto form navigado = navigation.
dis- (I->I): having to do with separation, in all possible directions.
sendi = to send dissendi = to broadcast
semi = to sow (seeds) dissemi = to scatter (seeds)
disaj = scattered
ek- (I->I): the beginning of an action described by the root.
iri = to go ekiri = to set out
vidi = to see ekvidi = to catch sight of
ek! = move it! get the lead out!
for- (I->I): away.
iri = to go foriri = to depart, leave
lasi = to leave forlasi = to abandon
fora = distant
mis- (I->I): wrongly, incorrectly, off the mark.
kompreni = to understand miskompreni = to misunderstand
ĵeti = to throw misĵeti = to throw wide of the
mark
misi = to miss, to err
A Japanese friend of mine once told me that she hoped I was right
in my use of the word misiloj to describe nuclear-armed missiles.
See also the suffix -il.
re- (I->I): back to the beginning again.
veni = to come reveni = to return
vidi = to see revidi = to see again
venki = to conquer revenki = to reconquer
ree = again
*retro- (I->I): in the opposite direction.
iri = to go retroiri = to go in the opposite
direction
paŝi = to step retropaŝi = to step back
ĉef- (O->O): greatest or most important.
ministro = minister (cabinet type) ĉefministro = Prime Minister,
Premier
urbo = city ĉefurbo = capitol
ĉefa = main
vir- (O->O): male equivalent of -in for beings whose sex is usually not
considered important (except, of course, to themselves...),
and whose root form is therefore considered neuter.
kato = cat virkato = tomcat
blato = cockroach virblato = buck cockroach
viro = man, male human
*cis- (O->A): on this side of.
luno = moon cisluna = cislunar, between earth and moon
limo = border cislima = on this side of the border
-aĉ (X->X): gives the word a shading of contempt, detestation.
ĉevalo = horse ĉevalaĉo = nag
domo = house domaĉo = hovel
aĉa = contemptible, disgusting
This is the affix that may be used to create pejoratives, as nigra
= black, nigrulo = a black person, nigrulaĉo = nigger. Since such
words are very uncommon in Esperanto, you will have to create them
as you go along, and accept 100% responsibility for your use of
them, not blame them on your upbringing or your teachers.
-eg (X->X): augments or strengthens the idea shown by the root.
domo = house domego = mansion
varma = hot varmega = boiling hot
ega = huge
-et (X->X): the opposite of -eg, it diminishes the idea shown by the root.
domo = house dometo = cottage
varma = hot varmeta = warm
eta = tiny
-um (Any to any): the affix equivalent of the preposition je, it has no definite
meaning; words with -um must almost be learned separately.
vento = wind ventumi = to ventilate
aminda = lovable amindumi = to pitch woo
umo = doohicky
*-if (O->I): to turn something into the root.
varma = hot varmifi = to thermalize
-ĉj (O->O): takes a man's name and turns it into an intimate form.
frato = brother fraĉjo = little brother
Johano = John Joĉjo = Jack
-nj (O->O): the female equivalent of the above.
frato = brother franjo = little sister
Johana = Joan Jonjo = Joanie
Note that these two forms do not function like ordinary suffixes,
but are usually attached after one of the first five letters of
the name or word. The Japanese Esperantist author Miyamoto Masao
once described the "beautiful people" as the ĉjo-njo-popolo -- an
interesting use of these affixes.
bo- (O->O): related through marriage.
patro = father bopatro = father-in-law
kuzo = cousin bokuzo = cousin-in-law
boa = related by marriage
eks- (O->O): former.
reĝo = king eksreĝo = former (abdicated) king
Sovetio = Soviet Union ekssovetio = former USSR
eksa = former
ge- (O->O): both sexes taken together.
patro = father gepatroj = parents
Sinjoro = Mr. gesinjoroj = Mr. and Mrs.
gea = male+female
Although this is not sanctioned by any grammatical rule, ge- is
also used with the singular to show a human relative of
unspecified gender: gepatro = parent.
mal- (X->X): turns a word into its opposite.
bela = beautiful malbela = ugly
amiko = friend malamiko = enemy
mala = opposite
pra- (X->X): distant in time (usually in the past) or relationship.
arbaro = forest praarbaro = forest primeval
nepo = grandson pranepo = great-grandson
patro = father prapatroj = forefathers
praa = before the dawn of...
*pseŭdo- (O->O): false.
scienco = science pseŭdoscienco = pseudoscience
nomo = name pseŭdonomo = pseudonym
nov-: has to do with newness.
edzino = wife nova edzino = new wife novedzino = bride.
The difference between nova edzino and novedzino is that, in the
first, the most important idea is that of wife; the newness is
simply a descriptor. In novedzino, however, the idea of newness
has come to have almost equal importance with the idea of wife; a
bride is not just a new wife, she is someone who has just become a
wife, who has crossed the threshhold from maidenhood (?) to
marriage. In effect, the newness of her wifehood is so great that
it distinguishes her, for the moment, from all other wives, even
novaj edzinoj.
dik-: thick.
fingro = finger dika fingro = thick finger dikfingro = thumb
Again, the thickness has become so important that it serves to
distinguish the thumb from all other fingers, no matter how thick
they may be; it is the thumb's distinguishing characteristic.
Kalocsay and Waringhien also point out that fractions (reciprocals) can be used as prefixes, e.g.
duon-: half.
frato = brother duonfrato = half-brother
In addition to adjective and fractional quasi prefixes, we have
the following four:
fi- (X->X): expressing indignation or disgust.
virino = woman fivirino = slut
bildo = picture fibildo = pornographic picture
fia = shameful
fuŝ- (X->X): screwed up.
verki = to write (to compose fuŝverki = to make it come
a work of art) out all wrong
fuŝi = to screw up
ne- (X->X): creates the negative (not, however, the opposite) of the root.
bona = good nebona = ungood malbona = bad
Many people believed for a long time that George Orwell based his
Newspeak -- the thought-control language of Oceania in the novel
1984 -- on Esperanto, based largely on Esperanto's use of the
prefix mal- to create opposites. The above list should indicate
that the spectrum between a word and its opposite is not totally
empty in Esperanto, as it is in Newspeak; we might, for instance,
add boneta and malboneta. Recent evidence indicates that Newspeak
was in fact a parody of Basic English, which Orwell apparently
despised as a corruption of real English.
vic- (O->O): second in rank, acting as regent for.
reĝo = king vicreĝo = viceroy
prezidento = president vicprezidento = vice-president
vico = line, place in line
There are also a number of specialized technical affixes which are not covered here.