Koni is the regular transitive verb for knowing an identifiable person or thing through acquaintance, experience, study, or recognition. You can koni a colleague, city, book, route, system, or language. For a proposition, answer, or other piece of information, Esperanto normally uses scii instead.
Complete regular paradigm
| Form | Function | Typical translation |
|---|---|---|
| koni | infinitive | to know, be acquainted with |
| konas | present indicative | know(s), is familiar with |
| konis | past indicative | knew, was acquainted with |
| konos | future indicative | will know, will become familiar with |
| konus | conditional | would know, would recognize |
| konu | volitive | know!, become familiar with! |
Mi konas ŝin de la universitato, sed ni ne estas proksimaj amikoj.
I know her from university, but we are not close friends.
Post kelkaj semajnoj vi pli bone konos la novan sistemon.
After a few weeks you will know the new system better.
The verb never agrees with person or number: mi konas, li konas, ili konas. The volitive konu is possible but less frequent than the infinitive in advice: Por pli bone koni la urbon, promenu ekster la turisma centro. It appears naturally in invitations such as Konu viajn rajtojn! “Know your rights!”
Koni takes a direct object
The person or thing known normally takes accusative -n, without a preposition.
Ĉu vi konas bonan dentiston en ĉi tiu kvartalo?
Do you know a good dentist in this neighborhood?
Ŝi bone konas la plej rapidan vojon al la flughaveno.
She knows the fastest route to the airport well.
Mi ne konas tiun romanon; kiu verkis ĝin?
I don't know that novel; who wrote it?
Adverbs can show degree and basis of familiarity: bone koni, apenaŭ koni, persone koni, koni laŭnome, koni nur supraĵe.
Mi konas la novan direktoron nur laŭnome; ni ankoraŭ ne renkontiĝis.
I know the new director only by name; we haven't met yet.
The object can also be a field, custom, body of work, or procedure viewed as a coherent entity: koni la lokajn kutimojn, koni la verkaron de aŭtoro, koni la programon. This does not necessarily imply total mastery.
Koni people
With a person, koni ranges from recognizing who someone is to knowing them well. Context and modifiers supply the degree.
— Ĉu vi konas Danielon? — Jes, ni laboris en la sama teamo pasintjare.
— Do you know Daniel? — Yes, we worked on the same team last year.
Mi apenaŭ konas la najbarojn, kvankam mi loĝas ĉi tie jam ses monatojn.
I barely know the neighbors, although I've lived here for six months.
English “know someone” maps closely to koni iun, but English sometimes means merely “know who someone is.” Esperanto can make that weaker relation explicit: Mi scias, kiu ŝi estas, sed mi ne konas ŝin persone.
Mi scias, kiu estas la kantisto, sed mi ne konas lin persone.
I know who the singer is, but I don't know him personally.
The first clause contains identifying information; the second denies personal acquaintance.
Places, works, and systems
Koni a place means having experiential familiarity with it, not merely knowing its location.
Mi konas Lisbonon sufiĉe bone por montri al vi kelkajn trankvilajn kvartalojn.
I know Lisbon well enough to show you a few quiet neighborhoods.
Ŝi scias, kie troviĝas la muzeo, sed ŝi ne konas la urbon.
She knows where the museum is, but she doesn't know the city.
The same distinction works with cultural works and systems. Koni la filmon means be familiar with the film; scii, kiu reĝisoris ĝin means know who directed it. Koni la programon means know the software or program through experience; scii, kiel malfermi dosieron identifies a particular procedure.
Ĉu vi konas ĉi tiun programon? Mi ne scias, kiel eksporti la dosieron.
Do you know this program? I don't know how to export the file.
With languages, koni Esperanton can mean be acquainted with or have knowledge of Esperanto, but it does not by itself specify speaking ability. Paroli Esperanton says one speaks it; scipovi paroli Esperanton explicitly describes the skill.
The central contrast with scii
| Use koni for | Use scii for |
|---|---|
| a person: koni Marian | a fact: scii, ke Maria venos |
| a place: koni la urbon | its location: scii, kie ĝi estas |
| a work: koni la libron | its author: scii, kiu verkis ĝin |
| a system: koni la regularon | a rule: scii la regulon |
Mi konas la hotelon, sed mi ne scias, ĉu ĝi havas liberajn ĉambrojn.
I know the hotel, but I don't know whether it has any available rooms.
The distinction is semantic, not a ban on particular nouns. A speaker can view la reguloj as information and say scii la regulojn, or view a whole regulatory system as familiar territory and say koni la regularon. What matters is information versus acquaintance.
For a focused decision guide, see Choosing Scii or Koni.
Getting to know and recognizing
The productive compounds separate a state from the transition into that state.
- ekkoni iun/ion — come to know, get to know, discover through acquaintance
- rekoni iun/ion — recognize something known before
- konatiĝi kun iu/io — become acquainted with someone or something
- konigi ion al iu — make something known, introduce it
Mi ekkonis miajn plej proksimajn amikojn dum somera Esperanto-renkontiĝo.
I got to know my closest friends during a summer Esperanto gathering.
Mi ne tuj rekonis ŝin pro ŝiaj novaj okulvitroj.
I didn't recognize her immediately because of her new glasses.
Dum la unua tago ni konatiĝis kun la aliaj membroj de la teamo.
During the first day we got acquainted with the other members of the team.
Ekkoni remains transitive and takes a direct object. Konatiĝi is intransitive and introduces the new acquaintance with kun. They often describe similar real events, but their grammar is not interchangeable.
La gvidanto konigis al ni la novan sekurecan proceduron.
The guide introduced the new safety procedure to us.
Here la proceduron is what is made known; al ni identifies the people who come to know it.
Participles and lexicalized forms
As a transitive verb, koni has both active and passive participles.
| Time relation | Active | Passive |
|---|---|---|
| ongoing | konanta — knowing | konata — known, familiar |
| earlier/completed | koninta — having known | konita — previously known |
| later/intended | kononta — about to know | konota — to become known |
Because knowing is normally a continuing state, konata is much more frequent than konita. It has also lexicalized as the ordinary adjective “known,” “familiar,” and sometimes “well-known.”
La restoracio estas konata pro sia simpla menuo kaj tre freŝaj ingrediencoj.
The restaurant is known for its simple menu and very fresh ingredients.
The noun konato means an acquaintance; nekonato means an unknown person or stranger, depending on context. These are ordinary noun participles, not irregular vocabulary.
Ŝi ne estas proksima amikino, nur malnova konato de la familio.
She isn't a close friend, just an old acquaintance of the family.
Register and frequency
Koni is high-frequency and neutral across conversation, journalism, literature, and academic prose. Konatiĝi kun is neutral in introductions and descriptions of learning a subject. Estas konate, ke... occurs in (formal) and academic writing, but if the complement is a proposition, active oni scias, ke... often states the informational relation more directly.
The root kon- and the regular paradigm are foundational. Its official gloss already includes knowledge through experience or study and recognition, so the range described here is not a recent extension. The strongest learner recommendation—reserve ke-clauses for scii—keeps that foundational distinction maximally clear.
Common Mistakes
Using koni before a ke-clause
❌ Mi konas, ke la vojo estas fermita.
Incorrect — a proposition is informational content for scii.
✅ Mi scias, ke la vojo estas fermita.
I know that the road is closed.
Using scii for personal acquaintance
❌ Mi scias Helenan de la universitato.
Incorrect for knowing Helena as a person.
✅ Mi konas Helenan de la universitato.
I know Helena from university.
Omitting accusative on the known entity
❌ Ĉu vi konas tiu verkisto?
Incorrect — the writer is the direct object of konas.
✅ Ĉu vi konas tiun verkiston?
Do you know that writer?
Adding kun after ordinary koni
❌ Mi konas kun ĉiuj en la oficejo.
Incorrect — koni is transitive and takes a direct object.
✅ Mi konas ĉiujn en la oficejo.
I know everyone in the office.
Copying English “get to know” word for word
❌ Mi ricevis koni ŝin dum la vojaĝo.
Incorrect — use ekkoni or konatiĝi kun for the beginning of acquaintance.
✅ Mi ekkonis ŝin dum la vojaĝo.
I got to know her during the trip.
Key Takeaways
- Koni is regular and transitive; the known person or entity takes accusative -n.
- It expresses familiarity, acquaintance, experiential knowledge, or recognition—not a whole proposition.
- Use scii for facts, answers, ke-clauses, and embedded questions.
- Ekkoni and rekoni take direct objects; konatiĝi introduces the acquaintance with kun.
- Frequent konata and konato show how the regular participle system produces established vocabulary.
Now practice Esperanto
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Start learning Esperanto →Related Topics
- Scii: To Know FactsA2 — Use scii for facts, answers, embedded questions, and know-how, and distinguish informational knowledge from acquaintance with koni.
- Paroli: To SpeakA2 — Use paroli with pri, kun, al, and language expressions, and distinguish the activity of speaking from saying a particular message.
- Direct ObjectsA1 — Learn which Esperanto verb complements are direct objects, how -n marks them, and how object marking remains stable when word order changes.
- Scii or Koni?A2 — Choose scii for facts, answers, and know-how, and koni for acquaintance or familiarity with people, places, works, and subjects.
- Confusing Scii and KoniB1 — Diagnose English ‘know’ by distinguishing informational knowledge with scii from familiarity and acquaintance with koni.
- Lexicalized ParticiplesC2 — Recognize participles whose repeated use has developed conventional adjective, noun, title, and discourse meanings beyond one immediate event.