Esperanto -us and -u: The Conditional and the Volitive in Full

The short version

-us is the conditional and it goes on both halves of an unreal sentence: se mi havus tempon, mi helpus vin. It carries no tense, so the same sentence covers if I had time and if I had had time, and the context settles which. It is also how you soften a request: mi volus, ĉu vi povus. Crucially, se does not demand -us at all - a real, open condition takes the ordinary tense (se vi venos, mi estos hejme), and over-applying -us after se is the commonest mistake in the area. The -u ending is the volitive, not merely the imperative: venu (come), ni iru (let us go), li venu (let him come), kion mi faru? (what should I do?), and it is what any verb becomes after ke when the main clause wants, asks, orders, permits or requires something - mi volas, ke vi venu. It never changes for tense either, so mi volis, ke li venu keeps the -u. Use the infinitive instead only when no new subject appears: mi volas veni.

The verb-tenses article laid out all five endings in one table and moved on, which was the right thing to do there: the point of that page is that Esperanto has no irregular verbs and nothing to memorise. -as, -is and -os genuinely need no more than a line each, because English has the same three tenses and you already know when to reach for them.

-us and -u do not work like that. They are the two endings where English gives you no matching instinct, and both of them cover more ground than the one-word gloss suggests. This page is the long version.

`-us`: the unreal, and only the unreal

-us is the would ending, and the shape of a conditional sentence in Esperanto is simpler than in any language you have met: put -us on both verbs.

Se mi tempon, mi vin. - If I had time, I would help you.
Se mi reĝo, mi al vi ĉion. - If I were king, I would give you everything.

English does something odd here that you have stopped noticing: it puts the if half into the past tense (if I had, if I were) and the other half into would. Two different mechanisms for one idea. Esperanto uses the same ending twice and stops.

That symmetry also means the trap is obvious once named. Do not translate English's past tense literally. is not if I had time; it is if I had time in the real, factual sense of whenever I had time back then. The unreal reading needs .

does not mean `-us`

This is the mistake to actually worry about. Learners meet -us in a conditional sentence, file it under "the ending", and then attach it to every they ever write.

-us marks a condition that is contrary to fact or genuinely improbable. A condition that might really happen takes the ordinary tense:

Sentence	Reading
Se vi morgaŭ, mi hejme.	Open. You might well come.
Se vi , mi feliĉa.	Unreal. We both know you are not coming.
Se li ne , li ne monon.	A general truth. No hypothesis at all.

Notice the first row: Esperanto uses the real future, , where English switches to the present (if you come tomorrow). English's habit of banning will after if is an English quirk, and Esperanto does not share it.

`-us` carries no tense

This surprises people, and it is deliberate. There is no past conditional ending. , means both if I knew, I would tell you and if I had known, I would have told you, and nothing in the grammar chooses between them. Context does, or an adverb: add or and the past reading is settled.

When the distinction genuinely matters you can build it: plus an -inta participle gives an explicit past hypothetical, . The compound-tenses article covers the machinery. It is correct, it is grammatical, and it is heavier than most sentences need.

Politeness is the same ending

-us softens. This one does map onto English, which is why it is easy:

paroli kun vi. - I would like to speak with you.
helpi min? - Could you help me?
vidi la domon. - I would like to see the house.

is not rude exactly, but it lands like I want a word. is I'd like a word. The implied condition is the polite fiction that you might say no.

And after

(as if) introduces something untrue by definition, so it pulls -us along with it:

Li parolas, li ĉion. - He talks as if he knew everything.
Ŝi rigardis min, ŝi ne min. - She looked at me as if she did not know me.

The trap `-us` is not for

English would has a second job that has nothing to do with conditions: reporting a future from a past standpoint. He said he would come. Esperanto does not use -us there.

Li diris, ke li . - He said he would come.

The tense inside a clause is measured from the moment of the main verb, not from now. He said it, and at that moment the coming was still in the future, so it is -os. Write and you have said something else entirely: he said he would come, if...

`-u`: the volitive, which is more than an imperative

Grammar books that call -u the imperative undersell it. Esperanto tradition calls it the volitive, from voli, to want, and that is the better name: -u marks an action that somebody wants to happen. Who wants it, and of whom, varies.

Form	English
!	Come!
.	Do not be afraid.
.	Let us go.
tuj.	Let him come at once.
?	What should I do?
la reĝo!	Long live the king!

Four things follow from that table.

Negation is just in front: . There is no do-support to learn, because there is no do in Esperanto to support anything with.

The subject can be stated when you need the contrast: tie, - you stay here, I will go. Bare is the neutral command; points a finger.

The first person singular is genuinely useful and beginners never use it. ? and ? are exactly what should I do and shall I open the window, and they are far more natural than anything built with .

The third person gives you a construction English has to fake with let. is everyone should do their own work, one clean clause.

plus `-u`

Here is where -u earns the name volitive. After any verb of wanting, asking, ordering, permitting, advising or requiring, a clause takes -u:

Mi volas, ke vi . - I want you to come.
Li petis, ke mi . - He asked me to stay.
La patro ordonis, ke la infanoj . - The father ordered the children to sleep.
Ŝi deziras, ke ni feliĉaj. - She wants us to be happy.
Necesas, ke ni tuj . - It is necessary that we leave at once.

English uses an infinitive for most of these (you to come, me to stay), which is why learners write , . That is not a sentence. If a new subject turns up, you need a full clause, and the verb in it takes -u.

Use the infinitive only when no new subject appears: , I want to come.

The rule cuts the other way too, and this matters. -u follows verbs of wanting, not verbs of saying or knowing. Reported fact keeps the ordinary tense:

Mi scias, ke vi . - I know you are coming.
Mi pensis, ke ŝi malsana. - I thought she was ill.

Ask yourself whether the clause reports something or demands something. Reports take tenses; demands take -u.

Two footnotes. (so that, in order that) always takes -u, because purpose is by definition something wanted: , . When the subject is unchanged, drop back to plus an infinitive: . And -u has no tense either, so a past main verb changes nothing: , .

The polite imperative is plus an infinitive: , . It is itself a -u form, of , to be so kind as to. A command telling you to be willing, which is a joke Zamenhof presumably enjoyed.

The one-line test

Ask what the sentence is doing.

Describing something that is not the case: -us.
Wanting something to be the case: -u.

Everything above is those two sentences with the cases spelled out.

What to take away

-us goes on both halves of an unreal conditional, and never appears in an open one.
-us has no tense; context or an adverb supplies the past.
-us is also the politeness ending: , .
-u covers commands, suggestions, third-person wishes and ?.
After , use -u when the main clause wants something and a tense when it reports something.
Neither ending changes for person or tense. Ever.

Practise: test yourself

Fill in the blank

0/6

Add -us or -u to the verb root, whichever the English asks for.

Se mi hav tempon, mi helpus vin. (if I had time) (An unreal condition takes -us in both halves.)
Ven kun ni! (come with us) (A direct command.)
Ni komenc nun. (let us begin now) (Ni plus -u is let us.)
Mi ŝat vidi la domon. (I would like to see the house) (Politeness is the conditional.)
Mi volas, ke vi rest ĉi tie. (I want you to stay here) (A new subject after ke.)
Se li est reĝo, li don___ al ni ĉion. (if he were king, he would give) (Both halves.)

Pick the right one

0/5

Does the second verb take the -u form or the infinitive -i?

Mi volas (veni). I want to come.
Mi volas, ke vi (veni). I want you to come.
Li petis, ke mi (resti). He asked me to stay.
Ŝi devas (labori). She has to work.
Mi laboras, por ke miaj infanoj (lerni). I work so my children learn.

Translation drill

0/6

Translate into Esperanto.

If I could, I would help you.
What should I do?
Let us go home.
Could you open the window?
He asked me to wait.
If you come tomorrow, I will be at home.

Mark the pattern

0/4

Is the condition unreal (needs -us) or open (takes the ordinary tense)?

unreal | open

If I were king, I would give you everything.
Which one is it?
If it is possible, I will come.
Which one is it?
If she had money, she would buy the house.
Which one is it?
If you want, we will begin now.
Which one is it?

Frequently asked questions

What is the difference between -us and -u in Esperanto?

-us is about what would happen and -u is about what should happen. Mi farus tion means I would do that, and implies a condition somewhere, stated or not. Mi faru tion means let me do that, or should I do that. The two get confused because English blurs them in polite speech, where would you and could you are really requests. In Esperanto the line is clean: if the sentence is hypothetical, use -us; if somebody wants the action performed, use -u.

Does se always take -us in Esperanto?

No, and assuming it does is the single commonest error learners make here. -us marks a condition that is contrary to fact or genuinely unlikely: se mi estus reĝo, mi donus al vi ĉion. A real, open condition takes the ordinary tense instead: se vi venos morgaŭ, mi estos hejme. Note that Esperanto uses the real future in that clause where English switches to the present (if you come tomorrow). The test is whether you are describing something that could actually happen. If it could, do not reach for -us.

How do I say let us in Esperanto?

Use ni plus the -u form: ni iru (let us go), ni komencu (let us begin), ni parolu pri tio (let us talk about that). There is no separate word for let, because the -u ending already carries the sense of somebody wanting the action to happen. The same trick works for any person: li venu is let him come, and ili atendu is let them wait.

When do I use ke with -u instead of an infinitive?

Use ke plus -u whenever the second action has a different subject from the first. Mi volas veni is I want to come, with one subject and therefore an infinitive. Mi volas, ke vi venu is I want you to come, with a new subject, and English's infinitive (you to come) becomes a full clause in Esperanto. This applies after every verb of wanting, asking, ordering, permitting and advising: li petis, ke mi restu; la patro ordonis, ke la infanoj dormu.

How do I say I would have done it in Esperanto?

Usually with plain -us and a bit of context, because -us carries no tense: se mi scius, mi dirus al vi covers both if I knew, I would tell you and if I had known, I would have told you. When the difference genuinely matters, the compound form estus plus an -inta participle marks the past explicitly: mi estus dirinta al vi. It is correct and it is heavy, and most fluent writers add an adverb like tiam instead.