The productive suffix -ul- forms a noun for a person characterized by what comes before it: juna → junulo “young person,” saĝa → saĝulo “wise person,” and miliono → milionulo “millionaire.” The defining feature may be a quality, habitual behavior, possession, physical characteristic, or relation.
English uses unrelated patterns—young person, coward, millionaire, opponent—and often forces a choice such as man or woman. Esperanto -ul- provides a coherent person-forming pattern. It does not, however, mean merely “someone who happens to do X once.” The feature must characterize the referent in the intended context.
The characteristic before the person
Place -ul- after the characteristic and before the noun ending -o:
| Characteristic | Person word | Interpretation |
|---|---|---|
| juna, young | junulo | a young person |
| riĉa, rich | riĉulo | a rich person |
| timi, to fear | timulo | a person characteristically fearful; coward |
| miliono, million | milionulo | a person possessing millions; millionaire |
The suffix is the semantic head: bonulo denotes a person, not a quality. The preceding base answers “characterized by what?” This head order is the reverse of an English phrase such as “wise person,” where the separate head noun comes last but the relationship is not expressed by a suffix.
La nova najbaro estas afabla bonulo, kiu ĉiam salutas nin.
The new neighbor is a kind, good person who always greets us.
Ne timu demandi; neniu ĉi tie konsideros vin stultulo.
Don't be afraid to ask; nobody here will consider you a fool.
The evaluation can be positive, negative, or neutral. -ul- itself does not praise or insult; stulta supplies the negative judgment, while saĝa supplies a positive one.
Qualities: the central pattern
Quality roots are the most direct input because they already describe a characteristic. Juna, honesta, riĉa, fremda, and kara yield ordinary person nouns.
La junuloj organizis senpagan koncerton en la parko.
The young people organized a free concert in the park.
Ĉu tiu riĉulo vere donacis la tutan sumon anonime?
Did that rich person really donate the whole amount anonymously?
La infanoj estas veraj karuloj por sia avino.
The children are real darlings to their grandmother.
That last example also illustrates sex reference: plural karuloj can naturally include children of any sex. In its systemic meaning -ul- denotes a person without specifying sex. In actual usage, especially in the singular, some speakers interpret an unmarked -ulo as male or prefer -ulino for a woman. The grammar and the usage tendency are not identical.
The clearest modern practice is:
- use the -ulo form when sex is irrelevant and context supports a person-neutral reading;
- add -in- when female sex is relevant: junulino;
- make male sex explicit lexically when relevant rather than assuming that -ul- always encodes it.
This is accepted variation in usage, not a new formal gender rule. See gender-neutral person nouns for the wider system.
Actions must be characteristic, not momentary
An action base with -ul- describes someone known for repeatedly or characteristically doing that action. Ŝerculo jokes often; drinkulo habitually drinks alcohol, normally excessively; timulo is characteristically fearful.
Li estas vera ŝerculo; eĉ dum streĉaj kunvenoj li trovas ion amuzan.
He is a real joker; even during tense meetings he finds something amusing.
Mi trinkis glason da vino, sed tio ne faras min drinkulo.
I drank a glass of wine, but that does not make me a habitual heavy drinker.
That contrast is crucial. A person currently speaking is parolanto “speaker,” not automatically parolulo. A person who works may be laboranto at that moment or laboristo by occupation. -ul- invites a characterizing inference, often about disposition or a recurring pattern.
Kiu ankoraŭ kuras sur la vojo? — Tiu kuranto kun la blua ĉemizo.
Who is still running on the road? — That runner in the blue shirt.
Here kuranto identifies the participant in the ongoing action. Kurulo would need a special context in which running characterizes the person; it is not the default equivalent of English “runner.”
Possessions, body features, and relations
A noun or more complex phrase can state what characterizes the person. Ĝibulo is a person characterized by a hump; milionulo by possessing one or more millions. Compound bases make the internal relation more explicit:
- longaj haroj → longharulo, a long-haired person
- granda kapo → grandkapulo, a person with a notably large head
- sen hejmo → senhejmulo, a homeless person
La longharulo ĉe la fenestro estas nia nova teknikisto.
The long-haired person by the window is our new technician.
La urbo malfermis noktan rifuĝejon por senhejmuloj.
The city opened a night shelter for homeless people.
Order matters. In longharulo, long- characterizes har-, and that whole unit characterizes the person. A mechanical imitation such as harlongulo does not transparently encode “person with long hair.” Affix stacking and scope treats such bracketing in detail.
Relational elements can also occur: kontraŭulo is a person who opposes someone or something—an opponent. Antaŭulo is a predecessor, and posteulo a successor or descendant. These are conventional extensions of “person characterized by a relation.”
Nia teamo respektas la kontraŭulojn, sed ni intencas venki.
Our team respects its opponents, but we intend to win.
-ul-, -ist-, -an-, and participles
These endings all make person nouns in common uses, but the semantic heads differ:
| Form | Core relation | Example |
|---|---|---|
| -ul- | person characterized by a feature | saĝulo, wise person |
| -ist- | person with an occupation, practiced activity, or doctrine | instruisto, teacher |
| -an- | member, inhabitant, or adherent | urbano, city resident |
| -ant-/-int- + -o | participant in an action or state | parolanto, speaker |
Mia instruisto estas tre pacienca homo, sed ne ĉiu pacienculo estas instruisto.
My teacher is a very patient person, but not every patient person is a teacher.
This minimal contrast separates occupation from characteristic. The word pacienculo is structurally possible and understandable, though pacienca homo/persono may be more idiomatic in a particular context. Productivity does not make every derived alternative equally frequent.
Participles already denote people
An active or passive participle with -o already functions as a person noun: parolanto “one who is speaking,” kurinto “one who ran,” konato “a person known to someone.” Adding -ul- is therefore normally redundant and may create a different, marked interpretation.
Ĉiuj partoprenantoj ricevos la programon retpoŝte.
All participants will receive the program by email.
Not partoprenantuloj. Likewise, mortinto is a dead person; a deliberately formed mortintulo would suggest someone characterized by looking or acting like the dead, an unusual expressive meaning. Konatulo is widely encountered as “acquaintance,” but traditional structural analysis favors konato. This is a genuine case where attested usage and the neat productive rule do not fully coincide.
Pedagogical recommendation: use the simple participial noun—konato, parolanto, kurinto—unless you intentionally need a special characterizing meaning. Recognize common konatulo, but do not generalize it into a rule that every participle takes -ul-.
Animals, figurative uses, and standalone ulo
Established biological group names extend -ul- beyond humans: mamuloj are mammals, characterized in the traditional term by mammary glands/nursing. Such words are lexical terms and should be learned as terms, not treated as permission to add -ul- freely to any animal description.
Figurative formations can personify objects. Nubskrapulo for a skyscraper is understandable and expressive, though nubskrapanto and other terms may also occur. Such coinages are (literary) or playful unless established in a domain.
The independent noun ulo means an unspecified person or “guy.” It is usually (informal) and can sound familiar, humorous, or mildly dismissive depending on tone.
Iu ulo lasis sian telefonon sur la vendotablo.
Some guy left his phone on the counter.
In neutral (formal) prose, prefer persono when no characterization is intended.
Common Mistakes
1. Using -ul- for one temporary action.
❌ La ulo, kiu nun legas la raporton, estas legulo.
Incorrect as a default description: reading once does not necessarily characterize the person.
✅ La persono, kiu nun legas la raporton, estas la leganto.
The person who is reading the report now is the reader.
2. Using -ul- where a profession requires -ist-.
❌ Mia filino volas fariĝi instruulo.
Incorrect for the profession ‘teacher’: this does not express the occupational role normally.
✅ Mia filino volas fariĝi instruisto.
My daughter wants to become a teacher.
3. Adding -ul- to a participle that already denotes a person.
❌ Ĉiu partoprenantulo ricevos insignon.
Incorrectly redundant in the ordinary meaning.
✅ Ĉiu partoprenanto ricevos insignon.
Every participant will receive a badge.
4. Preserving English phrase order inside a compound.
❌ La harlongulo portas verdan ĉapelon.
Incorrectly ordered for ‘the long-haired person.’
✅ La longharulo portas verdan ĉapelon.
The long-haired person is wearing a green hat.
5. Assuming that every singular -ulo necessarily means a man.
❌ Ŝi ne povas esti junulo, ĉar ŝi estas virino.
Incorrect as a categorical grammar rule: -ul- is systemically person-denoting, although usage can favor a male reading in some contexts.
✅ Ŝi estas unu el la junuloj, kiuj organizas la festivalon.
She is one of the young people organizing the festival.
Key Takeaways
- -ul- forms a person characterized by the preceding quality, habit, possession, feature, or relation.
- A momentary participant is normally expressed with a participle, not -ul-.
- Use -ist- for many occupations and practiced roles, and -an- for membership or inhabitancy.
- Compound order reveals scope: longharulo is “[long-haired] person.”
- The suffix is systemically sex-neutral, while singular usage can be contextually male-leaning; express relevant sex explicitly.
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Start learning Esperanto →Related Topics
- -ist-: Profession, Habitual Activity, Or IdeologyB1 — Use -ist- for people characterized by a profession, repeated activity, specialty, or doctrine without treating it as a simple equivalent of English -ist.
- -an-: Member, Inhabitant, Or AdherentA2 — Form nouns for members, inhabitants, and adherents with -an-, while learning where convention overrides mechanical word building.
- Affix Stacking and ScopeB2 — Interpret and build multi-affix Esperanto words by applying each layer in order and keeping the semantic head and participant roles clear.
- Gender-Neutral Person NounsA2 — How Esperanto uses neutral person, role, profession, and participant nouns without making the noun ending masculine.
- Natural Sex and Lexical GenderB1 — How sex can be part of a root’s meaning or added explicitly without creating grammatical gender agreement.
- Lexicalization and ConventionalityB2 — Understand why structurally transparent Esperanto words develop conventional meanings that cannot be predicted from morphology alone.