The suffix -uj- most basically forms a container intended to hold what comes before it: salo → salujo “salt container,” mono → monujo “wallet/purse,” and cindro → cindrujo “ashtray.” The container is the semantic head; the base names its expected contents, not normally its material or shape.
Two traditional extensions must also be recognized. With fruit or flower names, -uj- can name the plant that bears them: pomujo “apple tree.” With a people name, it can name that people's country: francoj → Francujo “France.” Those extensions are standard, but modern usage often prefers pomarbo and Francio, so this page separates the stable morphology from actual lexical choice.
The core container pattern
Place -uj- after the contents or activity and before the final ending:
| Base | Formation | Typical referent |
|---|---|---|
| salo | salujo | salt cellar or salt container |
| mono | monujo | wallet or purse |
| teo | teujo | container for tea leaves |
| cindro | cindrujo | ashtray |
Mi lasis mian monujon hejme, do ĉu vi povas pagi ĉi-foje?
I left my wallet at home, so can you pay this time?
La salujo estas malplena; ĉu estas pli da salo en la ŝranko?
The salt container is empty; is there more salt in the cupboard?
The exact shape is not encoded. A teujo may be a tin, box, or other purpose-built container. If shape or material matters, choose a more specific head such as skatolo, botelo, kruĉo, or sako.
Intended contents, not current contents
An -ujo word normally classifies a container by its purpose. An empty salujo remains a salt container, and a monujo does not stop being a wallet when all the money has been spent. Conversely, an improvised cup that temporarily contains coins does not automatically become a conventional monujo.
La monujo estas tute malplena, sed mi ankoraŭ havas mian bankkarton en la poŝo.
The wallet is completely empty, but I still have my bank card in my pocket.
Ni provizore metis la butonojn en tason, ĉar ni ne trovis taŭgan ujon.
We temporarily put the buttons in a cup because we could not find a suitable container.
This purpose-based reading parallels many English compounds, but Esperanto makes it easier to coin a general label. For a one-time relationship, ujo kun X or ujo por X may be more natural than declaring a new lexical category.
Contents are not material
This distinction exposes a common English-transfer error. English compounds allow “tin box” to mean a box made of tin. Esperanto ladujo instead means a container for sheet metal or tin material, because lado before -uj- is interpreted as the contents. A box made of sheet metal is ladskatolo.
La ŝraŭboj estas en ladskatolo, ne en la granda ladujo por ladpecoj.
The screws are in a sheet-metal box, not in the large container for pieces of sheet metal.
Likewise, lignujo is a container for wood, whereas ligna skatolo is a wooden box. Word order and the semantic head carry real information.
Ni konservas brullignon en lignujo kaj alumetojn en ligna skatoleto.
We keep firewood in a wood container and matches in a little wooden box.
An action base can identify what happens inside the container. Banujo is a tub in which somebody bathes; knedujo is a vessel in which dough is kneaded; konservujo is a container used for storage.
Metu la restaĵojn en hermetikan konservujon antaŭ ol fridigi ilin.
Put the leftovers in an airtight storage container before refrigerating them.
-ujo, -ingo, and -ejo
These three place-like suffixes differ in what they make the head:
| Form | Core relation | Example |
|---|---|---|
| -ujo | container whose contents are X | cigarujo, cigar case |
| -ingo | holder into which one X is partly inserted | cigaringo, cigar holder |
| -ejo | place where X is found or an activity occurs | abelejo, apiary |
Li prenis cigaron el la cigarujo kaj metis ĝin en la cigaringon.
He took a cigar from the cigar case and put it into the cigar holder.
That is a minimal contrast: the cigarujo contains or carries cigars, while the cigaringo grips one cigar for use. Similarly, an abelujo is an individual hive; an abelejo is a place where hives or bees are kept.
La abelbredisto havas dudek abelujojn en la abelejo malantaŭ sia domo.
The beekeeper has twenty hives in the apiary behind their house.
Plants that contain or produce fruit and flowers
Traditionally, a fruit, berry, or flower name plus -uj- can name the plant that bears it:
- pomo → pomujo, apple tree
- banano → bananujo, banana plant
- rozo → rozujo, rose plant
- vinbero → vinberujo, grapevine
The historical logic treats the plant as what “contains” or produces the named fruit or flower. The formation is standard and remains understandable, but it can collide with the literal container reading. A pomujo could be interpreted from context as an apple tree or an apple container.
La malnova pomujo ankoraŭ donas multe da fruktoj.
The old apple tree still produces a lot of fruit.
Ĉu vi plantis rozujon aŭ alian florplanton apud la pordo?
Did you plant a rosebush or another flowering plant beside the door?
Modern speakers often prefer the clearer pomarbo, bananplanto, rozplanto, and similar compounds. Both patterns are accepted. Pedagogical recommendation: recognize traditional plant -ujo words, but use an explicit plant head when a container interpretation would be plausible.
Traditional country names
With a people name, -uj- forms “the country of that people.” The initial capital belongs to the resulting proper name:
- francoj → Francujo
- germanoj → Germanujo
- japanoj → Japanujo
Ŝi kreskis en Francujo, sed nun loĝas en Belgio.
She grew up in France but now lives in Belgium.
Modern usage also has Francio, Germanio, and Japanio. The Academy's recommended-country-name guidance accepts -uj- and -i- alternatives for people-based country names, while often recommending whichever established form is most current or international. -i- is not a Fundamenta suffix, but it is firmly accepted in modern usage. -uj- can sound traditional to speakers who consistently prefer -io, but it is not archaic or incorrect.
This coexistence is a useful example of accepted variation and personal style: choose one recognized form consistently, while understanding the other without “correcting” it.
Do not attach -uj- mechanically to every country. Kanado, Brazilo, and Meksiko are established country roots; their inhabitants are kanadanoj, brazilanoj, and meksikanoj. The direction of derivation differs.
Ĉu vi diras Japanujo aŭ Japanio? — Mi uzas Japanio, sed ambaŭ formoj estas konataj.
Do you say Japanujo or Japanio? — I use Japanio, but both forms are familiar.
The short exchange reports accepted variation without pretending that every speaker's preference is the same.
Scope and longer compounds
Everything before -uj- is interpreted as the contents or defining use. Dentobrosujo is a container for a dentobroso “toothbrush”; the internal compound must be built first:
Mi metis la dentobroson en ĝian vojaĝan dentobrosujon.
I put the toothbrush in its travel case.
An English-influenced reversal such as brosdentujo fails because it does not first form the intended item. Longer words remain useful only while their internal relations are clear. A transparent phrase—ujo por dentobroso—is always available.
The independent noun ujo means a container of unspecified kind. As an ordinary root it has the container meaning, not the plant or country meanings.
Ne forĵetu la ujon; ni povas reuzi ĝin por rizo.
Don't throw the container away; we can reuse it for rice.
Common Mistakes
1. Reading the base as material rather than contents.
❌ Mi aĉetis lignujon por donaco, do la ujo estas el ligno.
Incorrect inference: lignujo means a container for wood, not necessarily one made of wood.
✅ Mi aĉetis lignan skatolon por la donaco.
I bought a wooden box for the gift.
2. Confusing a case with a fitted holder.
❌ La fumanto metis kvin cigarojn samtempe en la cigaringon.
Incorrect ordinary interpretation: a cigaringo is a fitted holder for one cigar.
✅ La fumanto konservis kvin cigarojn en la cigarujo.
The smoker kept five cigars in the cigar case.
3. Creating every country name with -uj-.
❌ Ŝi vojaĝos al Kanadujo en Aŭgusto.
Incorrect conventional country name: Kanado is already the established root.
✅ Ŝi vojaĝos al Kanado en Aŭgusto.
She will travel to Canada in August.
4. Assuming a logically possible container word is sufficiently precise.
❌ Donu al mi la teujojn.
Potentially unclear if you mean teapots, tea tins, or cups.
✅ Donu al mi la tekruĉojn; mi servos la teon.
Give me the teapots; I'll serve the tea.
Key Takeaways
- Core -uj- forms a container whose intended contents appear before the suffix.
- Material requires an adjective or a material-headed compound: ligna skatolo, not lignujo.
- Distinguish contents -uj-, fitted holder -ing-, and broader place -ej-.
- Plant -ujo words are standard but often compete with clearer -arbo or -planto forms.
- Traditional country -ujo is accepted alongside modern -io for appropriate people-based names; established root country names remain unchanged.
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Start learning Esperanto →Related Topics
- -ing-: Holder Or Socket For One ItemB1 — Use -ing- for a fitted holder, sheath, socket, or ring into which an item is partly inserted.
- -ej-: Place Associated With An ActivityA2 — Form names for places intended for an activity, occupants, goods, or another recognizable purpose with -ej-.
- -an-: Member, Inhabitant, Or AdherentA2 — Form nouns for members, inhabitants, and adherents with -an-, while learning where convention overrides mechanical word building.
- Compound Head OrderA2 — Interpret and build ordinary Esperanto compounds with the general head on the right and its modifier before it.
- Accepted Variation and Personal StyleC2 — Distinguish stable grammar, accepted alternatives, register choices, individual style, and genuinely nonstandard forms in Esperanto.