Confusing Scii and Koni | Esperanto Grammar

English uses know for two different relations: possessing information and being familiar with an entity. Esperanto normally keeps them apart. Use scii when the content is a fact, answer, question, or method; use koni when the object is a person, place, work, system, or other entity known through acquaintance or experience.

This is not a matter of attaching the right ending to one interchangeable root. The two verbs license different kinds of complements. A reliable correction therefore begins by identifying what “knowledge” means in the whole clause.

The core contrast

Verb	Knowledge presented as	Frequent complements
scii	information available to the mind	a factual object, ke-clause, embedded question, infinitive
koni	familiarity with an identifiable entity	a direct object naming a person, place, work, route, or system

Mi scias, kie estas la kafejo, sed mi ne konas ĝin.

I know where the café is, but I am not familiar with it.

Mi konas tiun kuraciston, sed mi ne scias lian telefonnumeron.

I know that doctor, but I do not know his phone number.

These minimal contrasts show why the English object alone is not enough. The café is the object of koni, but its location is information introduced by kie. The doctor is a person one can know, whereas the number is a piece of information one can scii.

💡

Replace English “know” mentally with either “be aware of the answer” or “be familiar/acquainted with.” The first points to scii; the second points to koni.

Use scii for propositions and answers

Scii can take an informational noun phrase as a direct object. That object carries accusative -n when required: scii la adreson, scii la regulon, scii la kialon. More revealingly, it can take a complete ke-clause or an embedded question.

Ĉu vi scias, ĉu la lasta buso jam foriris?

Do you know whether the last bus has already left?

Mi ne sciis, ke Nora laboras de hejme merkrede.

I did not know that Nora works from home on Wednesdays.

Neniu scias, kial la retejo ĉesis funkcii.

Nobody knows why the website stopped working.

The complement itself packages information: whether the bus left, the fact about Nora, or the reason for the failure. Koni cannot simply replace scii before these clauses. The pages on embedded yes-or-no questions and ki-correlative questions explain their internal form.

Scii + infinitive expresses learned know-how. This use can overlap with scipovi, which makes practical competence especially explicit.

Ŝi scias redakti filmetojn per sia telefono.

She knows how to edit videos on her phone.

Mi scias naĝi, sed mi ankoraŭ ne scipovas plonĝi.

I know how to swim, but I still do not know how to dive.

English often uses “can” for both skill and immediate possibility. Esperanto can keep them separate: Li scipovas stiri, sed hodiaŭ li ne povas veturi means that he has the skill but cannot drive today.

Use koni for familiarity and recognition

Koni is transitive. Its known entity is a direct object and normally takes -n: koni homon, koni urbon, koni libron. No preposition corresponding to English “with” is required.

Ĉu vi konas iun fidindan elektriston en la kvartalo?

Do you know a reliable electrician in the neighborhood?

Post tri jaroj ĉi tie, ni bone konas la urbon.

After three years here, we know the city well.

Mi apenaŭ konas ŝian verkaron, do kiun romanon vi rekomendas unue?

I barely know her body of work, so which novel do you recommend first?

Familiarity has degrees. Adverbs such as bone, apenaŭ, persone, and nur laŭnome say how well or on what basis someone knows the entity.

— Ĉu vi konas Amir? — Nur laŭnome; ni neniam renkontiĝis.

— Do you know Amir? — Only by name; we have never met.

Knowing who someone is does not entail acquaintance. Esperanto can state the difference directly.

Mi scias, kiu ŝi estas, sed mi ne konas ŝin persone.

I know who she is, but I do not know her personally.

The noun does not decide by itself

The distinction is conceptual, not a memorized list of nouns. A noun can denote information in one clause and a familiar whole in another. Compare scii la regulojn “know the rules as information” with koni la regularon “be familiar with the regulations as a system.”

La nova teknikisto konas la programon, sed li ankoraŭ ne scias ĉiujn klavarajn komandojn.

The new technician knows the program, but he does not yet know all the keyboard commands.

Likewise, scii pri means have information about something, while koni claims some familiarity with the thing itself.

Mi sciis pri la ekspozicio, sed nur hieraŭ mi ekkonis la laboron de la artisto.

I knew about the exhibition, but only yesterday did I become acquainted with the artist’s work.

This is where a word-for-word substitution fails. Ask what the speaker is presenting as known: a reportable fact, or an entity within their experience?

Difficult cases: names, languages, and routes

Some complements invite both viewpoints. Scii la nomon normally means that the name is available as information. Koni la nomon can instead mean that the name is familiar—perhaps the speaker has heard it before without remembering the person. The surrounding context must show which claim is intended.

Mi scias la nomon de la hotelo, sed ĝi ne sonas konata al mi.

I know the name of the hotel, but it does not sound familiar to me.

Mi konas tiun stratnomon, sed mi ne scias, kie la strato troviĝas.

That street name is familiar to me, but I do not know where the street is.

Languages also allow different claims. Koni Esperanton can mean being acquainted with the language or having some knowledge of it. It does not by itself guarantee speaking ability. Scii, kiel funkcias la akuzativo identifies a fact or procedure; scipovi paroli Esperanton makes practical competence explicit.

Ŝi konas Esperanton el interretaj filmetoj, sed ŝi ankoraŭ ne scipovas paroli ĝin.

She knows Esperanto from online videos, but she cannot speak it yet.

With a route, koni la vojon presents it as familiar terrain. Scii, kiun vojon elekti presents the answer to a practical question. This contrast is productive: the same real-world subject matter can be construed either as a known entity or as information about what to do.

💡

When both verbs seem possible with a noun, expand the idea into a clause. If the natural expansion begins ke, ĉu, kie, kiu, kiel, or another question word, scii is probably the intended viewpoint.

A repair procedure

When an English-based sentence feels doubtful, use this sequence:

Locate the full complement of “know,” not merely the following word.
If it can be paraphrased as “know that/whether/where/how” or “know the answer,” choose scii.
If it can be paraphrased as “be familiar or acquainted with,” choose koni.
Rebuild the complement: scii + clause/infinitive/informational object, but koni + accusative entity.

Do not let the presence of accusative -n decide between the verbs. Both can be transitive: Mi scias la respondon and Mi konas la respondinton are equally well formed. The first object is an answer held as information; the second is the person who gave it, known through acquaintance. Accusative marking tells you the noun phrase’s role after the verb has been chosen—it does not choose the verb for you.

Mi scias la rezulton, sed mi ne konas la homojn, kiuj faris la esploron.

I know the result, but I do not know the people who conducted the research.

❌ Mi konas, ke la kunveno komenciĝos je la naŭa.

Incorrect — changing an ending cannot repair the mismatch between koni and a proposition.

✅ Mi scias, ke la kunveno komenciĝos je la naŭa.

I know that the meeting will begin at nine.

The error is not just visible punctuation or object marking. The English analysis has selected the acquaintance verb for propositional content.

Norm, variation, and register

Both roots and the basic contrast are foundational. In neutral contemporary Esperanto, scii and koni are standard across informal, formal, and (academic) registers. Corpus usage also shows borderline noun objects where speakers choose a viewpoint: a body of rules, a language, or a software package may be treated as information mastered or as a domain familiar through experience.

That flexibility does not erase the central rule. Koni, ke... is not accepted neutral variation, and scii personon is not the normal way to express acquaintance. The pedagogical recommendation is to make the complement explicit when the intended viewpoint could be unclear.

Common Mistakes

Using koni with a factual clause

❌ Mi konas, ke la biblioteko estas fermita lunde.

Incorrect — the complement is a fact, not an entity known through familiarity.

✅ Mi scias, ke la biblioteko estas fermita lunde.

I know that the library is closed on Mondays.

Using scii for personal acquaintance

❌ Ĉu vi scias la novan najbarinon?

Incorrect if the question asks whether you are acquainted with the new neighbor.

✅ Ĉu vi konas la novan najbarinon?

Do you know the new neighbor?

Forgetting the accusative after koni

❌ Mi bone konas tiu kvartalo.

Incorrect — the familiar place is the direct object of konas.

✅ Mi bone konas tiun kvartalon.

I know that neighborhood well.

Treating knowing about as direct familiarity

❌ Mi konas pri la proponita ŝanĝo.

Incorrect — pri introduces information about a topic, so use scii pri here.

✅ Mi scias pri la proponita ŝanĝo, sed mi ne konas la detalojn.

I know about the proposed change, but I am not familiar with the details.

Copying English “if” into an embedded question

❌ Mi ne scias, se ili ricevis la mesaĝon.

Incorrect — se introduces a condition, not the unknown answer to a yes-or-no question.

✅ Mi ne scias, ĉu ili ricevis la mesaĝon.

I do not know whether they received the message.

Key Takeaways

Scii presents knowledge as information; koni presents it as familiarity with an entity. Both can have direct objects, so the repair cannot rely on surface form alone. Inspect the meaning and complement type, rebuild the complete Esperanto frame, and use an explicit clause when a noun permits more than one viewpoint.

Now practice Esperanto

Reading grammar gets you part of the way. The exercises are where it sticks — free, no signup needed.

Start learning Esperanto →