Dum marks temporal overlap: one event takes place within the duration of another time period, activity, or clause. It works both as a preposition—dum la kunveno—and as a clause introducer—dum ni kunvenis.
DUM before a Noun Phrase
As a preposition, dum stands before an expression denoting time or an activity understood as a span of time.
Mi ne kontrolis mian telefonon dum la kunveno.
I didn't check my phone during the meeting.
Dum la tuta nokto la vento forte blovis.
Throughout the whole night, the wind blew hard.
Ni babilis dum la vojaĝo al la flughaveno.
We chatted during the trip to the airport.
Vojaĝo is an event noun, so it supplies a temporal interval. A noun that is not normally temporal can also work when context clearly makes it stand for an activity, but do not stretch dum into a general relation marker.
The event need not occupy every second of the interval. Mi legis dum la flugo can mean that some reading occurred within the flight. Adding la tutan or an explicit duration makes full-span coverage clearer.
DUM before a Full Clause
Dum can also introduce a subordinate clause with its own subject and finite verb. English usually translates it as “while” or “as long as.”
Dum mi kuiris, mia frato aranĝis la tablon.
While I was cooking, my brother set the table.
Ne malfermu la pordon dum la forno funkcias.
Do not open the door while the oven is operating.
— Ĉu vi aŭdis la anoncon? — Ne, mi dormis dum ĝi estis farata.
— Did you hear the announcement? — No, I was sleeping while it was being made.
The two clauses can have different subjects: mi cooked while mia frato set the table. This distinguishes a full dum clause from an adverbial participle, whose understood subject normally matches the main-clause subject.
A clause introduced by dum can come first or second. A comma normally separates it when it comes first, as in Dum mi kuiris, .... When it follows a short main clause, the comma is often omitted.
DUM versus KIAM
Both can translate “when,” but they organize time differently. Dum foregrounds an interval and overlap; kiam identifies a time or occasion and can introduce a punctual event.
Dum mi atendis la buson, mi legis la novaĵojn.
While I was waiting for the bus, I read the news.
Kiam la buso alvenis, mi fermis la aplikaĵon.
When the bus arrived, I closed the app.
Waiting has duration and contains the reading, so dum fits. The bus's arrival is treated as the point that triggers closing, so kiam fits. Kiam can also cover extended situations; the contrast is one of viewpoint rather than a ban based on verb type.
DUM versus Duration in the Accusative
Esperanto can express duration either with dum + noun phrase or with an accusative measure.
Ni atendis dum du horoj.
We waited for two hours.
Ni atendis du horojn.
We waited for two hours.
Both are standard. With dum, the phrase explicitly creates a temporal interval. The accusative presents du horojn directly as the measure of the waiting. Do not combine the two case markings: after dum, say du horoj, not du horojn.
The accusative can be more compact; dum is useful when the phrase is long or when overlap, rather than mere measurement, deserves emphasis. See time duration in the accusative for the case pattern.
DUM versus EN
For time, dum places an activity inside a span without saying that a bounded task was completed. En + duration often gives the time needed to reach completion.
Mi legis dum du horoj, sed ne finis la libron.
I read for two hours, but I didn't finish the book.
Mi legis la tutan libron en du horoj.
I read the whole book in two hours.
This is a true aspectual contrast. Dum du horoj measures an activity. En du horoj frames an interval within which the complete result was achieved. English “for” versus “in” often parallels it, but choose from the event structure, not from the surface word alone.
DUM versus POR
Temporal por often presents an intended, allotted, or expected period; dum presents the period over which something actually happens.
Mi luis la apartamenton por tri monatoj.
I rented the apartment for a planned term of three months.
Mi efektive loĝis tie dum nur du monatoj.
I actually lived there for only two months.
The rental term is prospective or contractual; the residence is reported as an actual duration. In many everyday sentences either perspective may lead to a natural expression, but the distinction is useful when plan and reality differ.
No Accusative after DUM
The preposition already marks the temporal relation, so its complement normally has no -n.
Ŝi ne parolis dum la tuta intervjuo.
She did not speak during the whole interview.
Adjectives and nouns agree inside the phrase in the ordinary nominative form: dum la longa paŭzo, dum tri semajnoj, dum tiuj tagoj.
The rule changes only if a separate element has its own reason for accusative marking. In dum la intervjuo ŝi respondis tri demandojn, demandojn is the direct object of respondis, not part of the dum phrase.
DUM and the Infinitive
Traditional and clearest Esperanto uses dum before a full clause or an action noun, not directly before an infinitive. Instead of dum atendi, say:
Dum mi atendis, mi respondis kelkajn retmesaĝojn.
While I was waiting, I answered a few emails.
Dum la atendado mi respondis kelkajn retmesaĝojn.
During the wait, I answered a few emails.
Direct dum + infinitive is occasionally encountered under international influence, but many careful speakers find it awkward or nonstandard. The full clause is the best neutral recommendation, especially because it makes the subject explicit.
DUME and Compounds
The adverb dume has three established meanings:
- “during that time/meanwhile”;
- “for the moment/provisionally”;
- (formal/literary) “whereas/by contrast.”
Mi preparos la salaton; dume vi povas varmigi la supon.
I'll prepare the salad; meanwhile, you can heat the soup.
La definitiva dato ankoraŭ ne estas konata, do dume rezervu la unuan semajnfinon de Majo.
The final date is not known yet, so for now keep the first weekend of May free.
Compounds such as dumtempe “meanwhile,” dumviva “lifelong/during one's life,” and dumnokta “overnight/nocturnal during the night” preserve the temporal-overlap meaning. Use established transparent compounds; a separate dum phrase is usually clearer than an improvised long compound.
Register and Style
Both prepositional and clausal dum are neutral across spoken and written Esperanto. Repeating many dum clauses can make a narrative monotonous, so writers also use kiam, adverbial participles, or separate sentences when the temporal relation differs. That is a style choice, not a restriction on dum itself.
Common Mistakes
Adding accusative -N after DUM
❌ Ni restis interne dum la tutan matenon.
Incorrect — the preposition already marks the temporal role.
✅ Ni restis interne dum la tuta mateno.
We stayed inside throughout the morning.
Using DUM for a completion interval
❌ Ŝi finis la tutan raporton dum du horoj.
Incorrect for the intended meaning ‘within two hours’; this foregrounds activity during the interval.
✅ Ŝi finis la tutan raporton en du horoj.
She finished the entire report in two hours.
Using DUM for a punctual event
❌ Dum la buso atingis mian haltejon, mi ekstaris.
Incorrect for the intended meaning ‘when the bus reached my stop’; reaching the stop is treated as a point, not as a containing interval.
✅ Kiam la buso atingis mian haltejon, mi ekstaris.
When the bus reached my stop, I stood up.
Putting DUM directly before an infinitive
❌ Dum veturi, mi ne uzas mian telefonon.
Nonstandard in careful usage because <em>dum</em> does not traditionally introduce an infinitive.
✅ Dum mi veturas, mi ne uzas mian telefonon.
While driving, I do not use my phone.
Confusing DUM with DUME
❌ Mi kuiros; dum vi lavos la legomojn.
Incorrect for ‘meanwhile’ — <em>dum vi lavos la legomojn</em> is a subordinate clause, not an independent adverb.
✅ Mi kuiros; dume vi lavu la legomojn.
I'll cook; meanwhile, wash the vegetables.
Key Takeaways
- Dum places an event within the duration of a noun phrase or a full finite clause.
- Use dum for overlap, kiam for a time/occasion, and en + duration for time to completion.
- Duration can also be expressed directly with accusative -n, but never add that -n inside a dum phrase.
- Neutral Esperanto prefers a full clause or action noun after dum, not a bare infinitive.
- Dume means “meanwhile,” “for now,” and in elevated contexts “whereas.”
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Start learning Esperanto →Related Topics
- EnB1 — Use en for location within a place, period, or state, and add directional -n when something enters a new interior or result.
- PorB2 — Use por for an intended beneficiary, purpose, use, result, exchange, or the goal toward which an action is directed.
- TraB2 — Use tra for a path through an interior or distributed area, continuation throughout a period, and transmission through a channel.
- Time ClausesA2 — Connect events in time with kiam, dum, ĝis, antaŭ ol, post kiam, de kiam, and related clause introducers.
- Time DurationA1 — Express how long an event lasts by marking a time measure with -n or by using an explicit duration phrase.
- Time AdverbsB1 — Place events in time with Esperanto primitive particles and productive -e forms, including precise contrasts such as ĵus, tuj, and lunde.