Esperanto uses -u inside a subordinate clause when that clause presents an action as wanted, requested, required, permitted, prevented, or pursued as a goal. It is not a mechanical “subjunctive after ke.” The speaker chooses -u, an indicative ending (-as, -is, -os), or -us according to the subordinate action's meaning.
All uses on this page belong to neutral standard Esperanto. The governing principle comes from the foundational verb system: -u presents volition or aim and carries no tense of its own.
Within that complete system, veni is the tenseless infinitive “to come”; venas, venis, venos assert present, past, or future reality; venus presents imagined or conditional coming; and venu presents coming as wanted. None of these forms changes for person or number. This page focuses on why subordinate clauses select the last of those six forms.
The core pattern: a desired action after ke
A common pattern consists of a main clause expressing will, influence, or necessity, followed by ke + subject + verb in -u.
Mi volas, ke vi venu iom pli frue morgaŭ.
I want you to come a little earlier tomorrow.
La kuracisto petis, ke mi ripozu dum kelkaj tagoj.
The doctor asked me to rest for a few days.
Estas grave, ke ĉiuj ricevu la saman informon.
It is important that everyone receive the same information.
The ending remains -u with every subject: mi venu, vi venu, ŝi venu, ni venu, ili venu. It does not tell you who acts, so the subject normally has to be expressed inside the subordinate clause.
The volitive also has no past or future form. In petis, ke mi ripozu, the past main verb locates the request; the requested rest is interpreted relative to that request. In volas, ke vi venu morgaŭ, morgaŭ supplies future time. English often uses to, a plain verb, or a subjunctive form here, but Esperanto consistently marks the wanted status with -u.
Same subject: infinitive; different subject: ke + -u
When the person who wants and the person who acts are the same, Esperanto usually uses an infinitive after voli, deziri, preferi, and similar verbs.
Mi volas foriri antaŭ la trafikŝtopiĝo.
I want to leave before the traffic jam.
When the intended actor has its own subject, use a finite ke-clause.
Mi volas, ke vi restu ĝis la fino de la kunveno.
I want you to stay until the end of the meeting.
English permits I want you to stay: the object-like you is also understood as the subject of stay. Esperanto does not copy that construction as mi volas vin resti. The actor belongs explicitly inside ke vi restu. This distinction also prevents ambiguity:
Ŝi preferas kuiri hejme, sed ŝi preferas, ke ni manĝu kune.
She prefers to cook at home, but she prefers us to eat together.
The first preference concerns her own cooking; the second has ni as the subject of the desired meal.
What kinds of main clause license -u?
The important factor is meaning, not a memorized list of trigger words. Still, several recurring semantic groups are useful.
| Main-clause meaning | Common expressions | Subordinate interpretation |
|---|---|---|
| desire or request | voli, deziri, peti | what someone wants done |
| order or advice | ordoni, postuli, proponi, konsili | the required or recommended action |
| necessity or evaluation | estas necese, estas grave, estas pli bone | the action presented as desirable or required |
| permission or enablement | permesi, lasi, ebligi | the action made available |
| prevention or care | malebligi, eviti, zorgi, atenti | the result promoted or prevented |
La posedanto permesis, ke ni lasu la biciklojn en la korto.
The owner allowed us to leave the bicycles in the courtyard.
La teknikisto zorgos, ke nenio perdiĝu dum la ĝisdatigo.
The technician will make sure that nothing gets lost during the update.
With zorgi, atenti, and similar verbs, the subordinate clause describes the outcome being secured or avoided. The negative must match the intended logic: zorgu, ke ĝi ne rompiĝu means “make sure it does not break.”
Purpose clauses with por ke
Use por ke + subject + -u when one action is performed so that another desired result may occur. The second clause names an aim, not an established fact.
Mi skribis la adreson sur paperon, por ke vi ne forgesu ĝin.
I wrote the address on paper so that you wouldn't forget it.
Ni malfermu la fenestron, por ke iom da freŝa aero eniru.
Let's open the window so that some fresh air can come in.
If the same subject performs both actions, simple por + infinitive is normally more economical: Mi venis por helpi “I came to help.” Use por ke when the purpose needs its own stated subject or a full clause.
The difference between purpose and actual result is crucial:
Ŝi parolis malrapide, por ke ĉiuj komprenu.
She spoke slowly so that everyone would understand.
Ŝi parolis tiel klare, ke ĉiuj komprenis.
She spoke so clearly that everyone understood.
The first sentence tells us her aim; it does not guarantee success. The second reports the achieved result as a past fact, so it uses -is. This distinction is explained further on the purpose clauses page.
Reported commands versus reported statements
After a reporting verb, -u preserves the force of an original command or request. An indicative ending reports information instead.
La estro diris, ke ni venu je la oka.
The manager told us to come at eight.
La estro diris, ke ni venos je la oka.
The manager said that we will come at eight.
In the first sentence, the underlying message is Venu je la oka! In the second, it is Vi venos je la oka as a prediction or statement. English may use said to come, told us to come, or reported would; Esperanto marks the contrast directly on venu/venos.
Past reporting does not cause tense backshift. Ŝi petis, ke mi atendu keeps -u, because the waiting was requested rather than asserted as past.
Ke does not itself trigger the volitive
Many ke-clauses simply state facts, expectations, beliefs, or possibilities. These use the tense or mood that their own meaning requires.
Mi esperas, ke la trajno alvenos ĝustatempe.
I hope that the train will arrive on time.
Mi konsentas, ke vi pravas pri la prezo.
I agree that you are right about the price.
With esperi, ordinary usage treats the hoped-for event as an expected possibility and normally uses -os/-as/-is, not automatic -u. With konsenti, the indicative in vi pravas agrees with a proposition as true. But the same verb can introduce consent to a proposed action:
Mi konsentas, ke ni prokrastu la decidon ĝis morgaŭ.
I agree that we should postpone the decision until tomorrow.
Here prokrastu is the action to which the speaker consents. The lexical verb did not change; the relationship to the subordinate content did.
Likewise, factual possibility differs from an enabled opportunity:
Estas eble, ke ŝi alvenos post la naŭa.
It is possible that she will arrive after nine.
Nun finfine estas eble, ke mi iom ripozu.
Now at last it is possible for me to rest a little.
The first estimates what may be true and uses future -os. The second describes an opportunity for a desired action, so ripozu is natural.
Negation and prevention
With negative or preventive main verbs, do not insert a second ne unless the intended outcome itself is negative.
La gardisto malebligis, ke la vizitanto eniru sen bileto.
The guard prevented the visitor from entering without a ticket.
Malebligis already says that entry was prevented. Malebligis, ke li ne eniru would literally mean that the guard prevented his not entering—in context, the guard made him enter. By contrast, Atentu, ke vi ne falu genuinely aims at the negative result “you do not fall.” The logic is real and can be hard; translate the desired or prevented result, not the surface number of negatives in English.
-U versus -US inside a subordinate clause
Use -u for a desired action and -us for an imagined or conditional one.
Mi insistas, ke li venu kun ni.
I insist that he come with us.
Mi certas, ke li venus kun ni, se li ne devus labori.
I am sure that he would come with us if he didn't have to work.
The second clause is not a demand disguised by ke. It is a belief about a hypothetical consequence, so venus is conditional.
Common Mistakes
Using the indicative for the content of a request
❌ Mi volas, ke vi venas nun.
Incorrect for a desired action — venas presents the coming as a current fact.
✅ Mi volas, ke vi venu nun.
I want you to come now.
Leaving the subordinate verb as an infinitive
❌ La estro ordonis, ke ni foriri tuj.
Incorrect — a ke-clause needs a finite verb, and the ordered action takes -u.
✅ La estro ordonis, ke ni foriru tuj.
The manager ordered us to leave immediately.
Using -U after every ke
❌ Mi scias, ke la vendejo fermu je la sesa.
Incorrect for a known schedule — the closing is stated as a fact, not desired.
✅ Mi scias, ke la vendejo fermos je la sesa.
I know that the shop will close at six.
Adding an extra negative after malebligi
❌ La neĝo malebligis, ke ni ne vojaĝu.
Incorrect for ‘prevented us from travelling’ — this says the snow prevented our not travelling.
✅ La neĝo malebligis, ke ni vojaĝu.
The snow prevented us from travelling.
Backshifting a requested action into -IS
❌ Ŝi petis, ke ni atendis en la vestiblo.
Incorrect for a reported request — atendis asserts that the waiting happened.
✅ Ŝi petis, ke ni atendu en la vestiblo.
She asked us to wait in the lobby.
Key Takeaways
- Use ke + subject + -u for requested, required, permitted, prevented, or otherwise desired actions.
- Use an infinitive when the controlling and acting subject are the same; use a ke-clause when the desired action has its own subject.
- Por ke + -u expresses purpose; a factual result takes the appropriate indicative tense.
- Ke does not trigger a mood by itself: facts and expectations use real forms, imagined consequences use -us, and volitional content uses -u.
- The volitive is invariant and timeless; the main clause and context locate the action in time.
Related Topics
- The Volitive in -UB1 — Learn how invariant -u expresses commands, requests, wishes, proposals, purposes, and desired actions in subordinate clauses.
- The Volitive for CommandsA2 — Learn how Esperanto uses invariant -u for direct commands, prohibitions, instructions, and third-person directives with appropriate politeness.
- Wishes and ExhortationsA2 — Use Esperanto -u for inclusive let's-exhortations, personal resolutions, third-person wishes, blessings, and hoped-for outcomes.
- Ke-ClausesA2 — How finite clauses introduced by ke function as statements, subjects, objects, complements, and content descriptions.
- Purpose Clauses with Por KeA2 — Express intended outcomes with por ke and the volitive, and choose correctly between a finite purpose clause and por plus an infinitive.
- Reported CommandsB2 — Report commands, requests, advice, and proposals with ke plus the volitive, or with controlled infinitive constructions where appropriate.