# Esperanto lesson 10: word building, prefixes and suffixes

Source: https://esperantopedia.org/learn/course/lesson-10/
Language: en
Updated: 2026-10-08

> One root, many words: lerni gives lernejo "school" and malsanulejo means "hospital". Learn mal-, -ej-, -ist-, -in-, -et-, -eg-, -ul- and -an-.

In this lesson you learn the trick that makes Esperanto vocabulary grow fast: building words from parts. A root plus a prefix or suffix plus an ending gives a new word you can understand without a dictionary: *lern·ej·o* "learn + place + noun" = "school". You will learn eight of the most useful affixes – *mal-, -ej-, -ist-, -in-, -et-, -eg-, -ul-* and *-an-* – and see how one root grows into a whole family of words.

## Dialogue

The congress has an evening of games. Juma, who ran the online group from Lesson 1, hosts a word game.

| Esperanto | English |
|---|---|
| **Juma:** Bonvenon al la vortludo! La reguloj estas simplaj: mi diras vorton, kaj vi faras novajn vortojn. | Welcome to the word game! The rules are simple: I say a word, and you make new words. |
| **Juma:** La unua vorto: *granda*. Kio estas la malo? | The first word: *granda* "big". What's the opposite? |
| **Ana:** Malgranda! | Small! |
| **Juma:** Ĝuste! Kaj tre, tre granda? | Right! And very, very big? |
| **Tomo:** Grandega! Kiel la kongresejo! | Huge! Like the congress hall! |
| **Juma:** Bonege. Nun: *lerni*. Kiel ni nomas la lokon, kie oni lernas? | Great. Now: *lerni* "to learn". What do we call the place where people learn? |
| **Keiko:** Lernejo! | School! |
| **Juma:** Kaj la personon, kiu instruas tie? | And the person who teaches there? |
| **Ana:** Instruisto – aŭ instruistino, se ŝi estas virino. | A teacher – or *instruistino*, if she's a woman. |
| **Juma:** Perfekte! Kaj ni ĉiuj ĉi tie, ĉe la kongreso? | Perfect! And all of us here at the congress? |
| **Tomo:** Ni estas kongresanoj! | We're congress participants! |
| **Juma:** Jes! Lasta vorto: *domo*. Kaj malgranda domo? | Yes! Last word: *domo* "house". And a small house? |
| **Keiko:** Dometo! | A little house! |
| **Juma:** Kaj persono, kiu estas juna? | And a person who is young? |
| **Ana:** Junulo! Kiel ni! | A young person! Like us! |
| **Juma:** Ha ha! Gratulon – vi ĉiuj gajnis! | Ha ha! Congratulations – you've all won! |

*Kie* and *kiu* also join two parts of a sentence: *la lokon, kie oni lernas* – "the place where people learn"; *la personon, kiu instruas* – "the person who teaches".

## New words

| Esperanto | English | Notes |
|---|---|---|
| *vortludo* | word game | *vorto* "word" + *ludo* "game" |
| *regulo* | rule | |
| *simpla* | simple | |
| *diri* | to say | |
| *malo* | the opposite | *mal-* used as a word |
| *loko* | place | |
| *oni* | one, people, you (in general) | *kie oni lernas* "where people learn" |
| *instrui* | to teach | *lerni* "to learn" |
| *persono* | person | |
| *virino* | woman | *viro* "man" |
| *domo* | house | |
| *juna* | young | *maljuna* "old (of people)" |
| *lasta* | last | |
| *gajni* | to win | |
| *gratulon!* | congratulations! | |
| *se* | if | |
| *lernejo* | school | *lern-* + *-ej-* |
| *instruisto* | teacher | *instru-* + *-ist-* |
| *kongresano* | congress participant | *kongres-* + *-an-* |
| *dometo* | little house, cottage | *dom-* + *-et-* |
| *grandega* | huge | *grand-* + *-eg-* |
| *junulo* | young person | *jun-* + *-ul-* |
| *malsanulejo* | hospital | *mal-* + *san-* + *-ul-* + *-ej-* |

## Grammar

### How word building works

An Esperanto word is made of a root, optional affixes and an ending. The ending tells you the word class – *-o* noun, *-a* adjective, *-e* adverb, *-i* verb – and the affixes add meaning. The *Fundamento* (rule 11) says new words are formed by joining existing parts. Read more on the [word building](https://esperantopedia.org/grammar/word-building/) page.

lernejo = school | lern = learn
kongresano = congress participant | kongres = congress
malsanulejo = hospital | san = healthy

### Eight affixes to start with

Esperanto has 10 official prefixes and 31 suffixes. These eight cover a large share of everyday words. See the full lists of [prefixes](https://esperantopedia.org/grammar/prefixes/) and [suffixes](https://esperantopedia.org/grammar/suffixes/).

| Affix | Meaning | Examples |
|---|---|---|
| *mal-* | the opposite | *granda* → *malgranda* "small"; *fermi* "to close" → *malfermi* "to open" |
| *-ej-* | place for | *lerni* → *lernejo* "school"; *kafo* → *kafejo* "café" |
| *-ist-* | profession, specialist | *instrui* → *instruisto* "teacher"; *programo* → *programisto* "programmer" |
| *-in-* | female | *amiko* → *amikino* "female friend"; *instruisto* → *instruistino* "female teacher" |
| *-et-* | small, weaker | *domo* → *dometo* "cottage"; *ridi* "to laugh" → *rideti* "to smile" |
| *-eg-* | big, stronger | *granda* → *grandega* "huge"; *pluvo* "rain" → *pluvego* "downpour" |
| *-ul-* | person with that quality | *juna* → *junulo* "young person"; *riĉa* "rich" → *riĉulo* "rich person" |
| *-an-* | member, inhabitant | *kongreso* → *kongresano* "participant"; *urbo* → *urbano* "town dweller" |

:::match What does the affix mean?
mal- = the opposite
-ej- = place for
-ist- = profession
-et- = small, weaker
-eg- = big, stronger
-ul- = person with that quality
:::

### Change the ending, change the word class

The same root can become a noun, adjective, adverb or verb just by changing the ending.

| Ending | Word | Meaning |
|---|---|---|
| *-o* (noun) | *kanto* | song |
| *-i* (verb) | *kanti* | to sing |
| *-a* (adjective) | *kanta* | singing, of song |
| *-e* (adverb) | *kante* | singing, in song |

:::ending One root, four endings
- o a e i
? a song
= kant[o]
? Ana likes to sing.
= Ana ŝatas kant[i].
? The work is interesting.
= La labor[o] estas interes[a].
? Tomo cooks well.
= Tomo kuiras bon[e].
? a healthy boy
= san[a] knab[o]
:::

### One root, a whole family

Learn the root *san-* "healthy" and you already understand a family of words. Our [Esperanto dictionary](https://esperantopedia.org/dictionary/) shows the parts and the word family of every entry.

| Word | Meaning |
|---|---|
| *sana* | healthy |
| *sano* | health |
| *malsana* | ill, sick |
| *malsano* | illness |
| *malsanulo* | patient, sick person |
| *malsanulejo* | hospital |
| *saniĝi* | to get well |

The suffix *-iĝ-* in *saniĝi* means "to become": you have already met it in *renkontiĝi*, *nomiĝi*, *komenciĝi* and *turniĝi*.

### Affixes can stand alone

Because affixes are roots in their own right, they can take endings and become words: *malo* "the opposite", *ejo* "a place", *eta* "tiny", *ega* "enormous", *ino* "a female". The adverb *ege* "extremely" is especially common: *ege bona* – "extremely good".

:::write Build one word
? a place for eating (*manĝi* + *-ej-*)
= manĝejo
? a small table (*tablo*)
= tableto
? a cook – someone whose job is cooking (*kuiri*)
= kuiristo
! kuirejo → *Kuirejo* is a kitchen, a place for cooking. For a person whose job it is, use *-ist-*.
? a very strong wind, a gale (*vento*)
= ventego
? a member of the family (*familio*)
= familiano
:::

## Practice

:::quiz Lesson 10 practice
? What does *malbela* mean?
- very beautiful
- ugly *
- beautiful place
? Which suffix means "place"?
- -ej- *
- -et-
- -eg-
? Translate with one word: "a female teacher"
= instruistino
? What is a *dometo*?
- a big house
- a small house *
- a housewife
? What does *mal·san·ul·ej·o* mean?
- hospital *
- doctor
- medicine
? Translate with one word: "huge, very big"
= grandega
? Which word means "a congress participant"?
- *kongresisto*
- *kongresano* *
- *kongresejo*
? Translate with one word: "a young person"
= junulo
? What is the opposite of *nova*?
= malnova
? Which word names a profession?
- *lernejo*
- *instruisto* *
- *lernanto*
:::

## Culture corner

Esperanto has its own literature, written and translated since 1887. Writers such as Kálmán Kalocsay, Julio Baghy and the Scottish poet William Auld wrote original poetry and novels, and Auld translated *The Lord of the Rings* (1995–97). Nobody has counted all Esperanto books; one overview estimates about 10,000 titles by around 2000. Explore [Esperanto literature](https://esperantopedia.org/about/literature/).

## Common questions

### How many affixes does Esperanto have?

There are 10 official prefixes and 31 official suffixes, plus six suffixes for participles. You don't need them all at once; the eight in this lesson cover a large part of everyday speech.

### Can I invent my own words?

Yes, within limits. If a combination is clear and no common word already exists, people will understand it. If a well-known word already exists, use it: everybody understands *malsanulejo* "hospital" (*hospitalo* is also found).

### Is *malbona* really the normal word for "bad"?

Yes. *Malbona* "bad" is the standard word, as is *malgranda* "small". Learners sometimes find *mal-* words strange at first, but every speaker uses them.

## Sources

- [Fundamento de Esperanto – grammar in English (rule 11, compound words)](https://www.akademio-de-esperanto.org/fundamento/gramatiko_angla.html)
- [PMEG: Vortfarado – principoj (word-building principles)](https://bertilow.com/pmeg/vortfarado/principoj/index.html)
- [PMEG: Prefiksoj (list of ten)](https://bertilow.com/pmeg/vortfarado/afiksoj/prefiksoj/index.html)
- [PMEG: Sufiksoj (list of 31)](https://bertilow.com/pmeg/vortfarado/afiksoj/sufiksoj/index.html)
- [PMEG: MAL](https://bertilow.com/pmeg/vortfarado/afiksoj/prefiksoj/mal.html)
- [Universala Vortaro (Fundamento, 1905)](https://www.akademio-de-esperanto.org/fundamento/universala_vortaro.html)
- [Wikipedia: William Auld](https://en.wikipedia.org/wiki/William_Auld)
- [Wikipedia: Translations of The Lord of the Rings](https://en.wikipedia.org/wiki/Translations_of_The_Lord_of_the_Rings)
- [EBSCO Research Starters: Esperanto](https://www.ebsco.com/research-starters/social-sciences-and-humanities/esperanto)