Kiam: The Question/Relative Time Correlative | Esperanto Grammar

Kiam asks or relates time: Kiam vi revenos? “When will you return?” and Kiam vi revenos, telefonu al mi “When you return, call me.” It can introduce a direct question, an embedded question, or a relative time clause. It never takes plural -j or accusative -n.

The patterns on this page are neutral in conversation and writing. In careful usage, kiam asks for a time or occasion; duration and exact clock time have more specific expressions.

Kiam in the 5×9 table

Esperanto’s 45 table words pair five fixed initial series with nine fixed semantic domains. Ki- gives question or relative force; -am gives the time or occasion domain.

Dimension	Relevant forms
Initial series	ki- question/relative, ti- demonstrative, i- indefinite, ĉi- universal, neni- negative
Final domains	-u individual, -o thing, -a kind, -es possessor, -e place, -am time, -al reason, -el manner, -om quantity
The -am column	kiam, tiam, iam, ĉiam, neniam
The ki- row	kiu, kio, kia, kies, kie, kiam, kial, kiel, kiom

The final -am is a fixed table-word ending. It does not receive ordinary plural or case markers, so forms such as kiamj and kiamn are impossible in the standard language.

See The Table-Word System for the full grid and Time Clauses for a broader comparison of temporal connectors.

Direct questions about time

Use kiam when an answer may be a day, date, period, moment, or occasion.

Kiam komenciĝos la sekva kurso?

When will the next course begin?

— Kiam vi laste parolis kun ŝi? — Antaŭ du semajnoj.

— When did you last speak with her? — Two weeks ago.

Kiam estas plej bone viziti la insulon?

When is it best to visit the island?

Kiam itself is neither past nor future. The verb and context locate the time: kiam okazis, kiam okazas, kiam okazos.

For an exact clock hour, normative usage prefers je kioma horo:

Je kioma horo foriras la lasta trajno?

At what time does the last train leave?

An answer such as je la dudek-dua kaj dek kvin matches that precise question. Ordinary Kiam foriras la trajno? is still natural when any useful time answer is acceptable.

Kiam versus kiom da tempo

Kiam asks the location of an event in time. Kiom da tempo or kiom longe asks its duration.

Kiam vi loĝis en Romo? — En 2024.

When did you live in Rome? — In 2024.

Kiom longe vi loĝis en Romo? — Dum ses monatoj.

How long did you live in Rome? — For six months.

English learners sometimes let when and how long blur in questions about past periods. Esperanto requires the semantic choice: time point/occasion kiam, quantity of time kiom longe.

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Match the expected answer: morgaŭ / en Julio / post la kunveno → kiam; du horojn / dum semajno → kiom longe.

Embedded questions

The same word introduces an indirect question. It remains invariant and belongs to the embedded clause.

Mi ne scias, kiam la teknikisto alvenos.

I don't know when the technician will arrive.

Ĉu vi memoras, kiam ni unue renkontiĝis?

Do you remember when we first met?

A temporal preposition may narrow the requested endpoint or starting point:

Ŝi demandis, ĝis kiam la biblioteko restos malfermita.

She asked until when the library would remain open.

Here ĝis belongs directly with interrogative kiam: the unknown answer is an ending time.

Relative kiam and time clauses

Relative kiam links a clause to a time expression, often explicit tiam or a time noun.

Mi telefonos al vi tiam, kiam mi havos la rezultojn.

I will call you when I have the results.

Mi ankoraŭ memoras la vesperon, kiam ni perdis la vojon.

I still remember the evening when we got lost.

Very often tiam is left understood:

Kiam la pluvo ĉesos, ni eliros.

When the rain stops, we'll go out.

The kiam-clause supplies the time setting for the main clause. When the statement is general or repeated, kiam can mean “whenever/on occasions when”:

Kiam mi laboras hejme, mi tagmanĝas pli frue.

When I work from home, I have lunch earlier.

This is not plural marking on kiam; repeated occasions come from the clause’s generic meaning.

Future time: do not copy English tense

English normally says “when you arrive” with present tense even though the arrival is future. For a straightforward future event, Esperanto normally uses the future tense that the subordinate event actually has.

Kiam vi alvenos morgaŭ, sendu al mi mesaĝon.

When you arrive tomorrow, send me a message.

Both alvenos and the future context point forward. Esperanto does not impose the English ban on will in a future time clause.

Present tense can occasionally present a scheduled future event as already fixed or imminent, just as it can in an independent Esperanto clause. That is a separate discourse choice, not a rule triggered by kiam; the reliable learner default for a genuinely future event is -os.

Kiam ŝi finis la raporton, ŝi sendis ĝin al la kliento.

When she finished the report, she sent it to the client.

Here both events are past. Choose tense from time reference, not from the presence of kiam.

Prepositions with a whole kiam-clause

In relative time clauses, post kiam and de kiam relate the main event to the entire subordinate event.

Post kiam ni finis la kunvenon, ni iris kune vespermanĝi.

After we finished the meeting, we went to dinner together.

De kiam ŝi translokiĝis ĉi tien, ni vidas ŝin multe pli ofte.

Since she moved here, we see her much more often.

In post kiam ni finis, post governs the whole idea “when we finished.” For “before” plus a finite clause, established usage normally prefers antaŭ ol:

Kontrolu la adreson antaŭ ol vi sendos la pakaĵon.

Check the address before you send the package.

Kiam versus dum and se

Kiam locates an event at a time or occasion. Dum foregrounds two situations continuing simultaneously; se makes one event a condition whose realization is not presented as given.

Kiam mi eniris, ili diskutis pri la buĝeto.

When I came in, they were discussing the budget.

Dum ili diskutis pri la buĝeto, mi prenis notojn.

While they were discussing the budget, I took notes.

Se vi venos al la festo, informu min ĝis vendredo.

If you come to the party, let me know by Friday.

Use kiam when the time relation is asserted or expected; use se when occurrence itself is conditional. Context can make the pragmatic boundary subtle, but the semantic contrast is real.

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English when can introduce both a time and a condition. Esperanto kiam locates an occasion; se explicitly presents a condition.

Common Mistakes

1. Adding accusative -n

❌ Kiamn vi revenos de la vojaĝo?

Incorrect — -am correlatives never take -n.

✅ Kiam vi revenos de la vojaĝo?

When will you return from the trip?

2. Asking duration with kiam

❌ Kiam longe daŭris la intervjuo?

Incorrect — the question asks quantity of time.

✅ Kiom longe daŭris la intervjuo?

How long did the interview last?

3. Using past tense for a future completion

❌ Kiam vi finis la taskon morgaŭ, sendu la dosieron.

Incorrect — finis locates the completion before the present, but morgaŭ is future.

✅ Kiam vi finos la taskon morgaŭ, sendu la dosieron.

When you finish the task tomorrow, send the file.

4. Using kie with a time antecedent

❌ Venis tago, kie ni devis decidi.

Incorrect in the standard table-word distinction — tago is time, not place.

✅ Venis tago, kiam ni devis decidi.

A day came when we had to decide.

5. Inventing a hybrid clock-time question

❌ Kiam horo komenciĝas la filmo?

Incorrect — this mixes kiam with an ordinary noun phrase.

✅ Je kioma horo komenciĝas la filmo?

At what time does the film start?

Key Takeaways

Ki- supplies question/relative force; -am supplies time or occasion.
Kiam is invariant: it takes neither -j nor -n.
Use kiom longe for duration and je kioma horo for an exact clock hour.
Relative kiam can correspond to explicit or understood tiam and often introduces a time clause.
Use actual Esperanto tense in future time clauses: kiam vi alvenos, not an automatic copy of English present tense.

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