Esperanto Verbs: The Complete System | Esperanto Grammar

Every Esperanto verb belongs to one compact system. Replace the final -i of the dictionary form with -as, -is, -os, -us, or -u, and you have the core forms of the verb. There are no irregular verbs and no different endings for “I,” “she,” or “they.”

The six endings

The endings do more than locate an event in time. They also show how the speaker presents it: as an action merely named, as an actual situation, as imagined, or as wanted.

Ending	Traditional label	Core meaning	Example
-i	infinitive	names an action or state without tense or mood	labori — to work
-as	present	presents an actual current, habitual, or generally valid situation	laboras — works/is working
-is	past	presents an actual situation before now	laboris — worked/was working
-os	future	presents a situation expected after now	laboros — will work
-us	conditional	presents an imagined or conditional situation, without encoding time	laborus — would work
-u	volitive	presents an action as wanted, requested, commanded, or purposed	laboru — work!/should work

Mi laboras hejme hodiaŭ.

I am working at home today.

Hieraŭ mi laboris en la oficejo, kaj morgaŭ mi laboros tie denove.

Yesterday I worked at the office, and tomorrow I will work there again.

Mi laborus kun vi, se mi havus tempon.

I would work with you if I had time.

Bonvolu labori pli silente, por ke la bebo dormu.

Please work more quietly so that the baby can sleep.

The three tense forms -as, -is, -os belong to the real or indicative system. -us and -u are not additional tenses. A conditional situation may concern the present, past, or future; context supplies the time. The -u form likewise expresses will or purpose rather than a location on a timeline.

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Learn the endings as a meaning map: -i names, -as/-is/-os assert in time, -us imagines, and -u wills. Calling all six “tenses” hides the most useful distinction.

One form for every subject

Esperanto verbs do not agree with their subject in person or number. The subject changes; the verb does not.

Subject	Present of paroli
mi	mi parolas
vi	vi parolas
li / ŝi / ĝi	li / ŝi / ĝi parolas
ni	ni parolas
ili	ili parolas

Mi parolas Esperanton, sed miaj gepatroj parolas nur la francan.

I speak Esperanto, but my parents speak only French.

Ĉu vi komprenas min? — Jes, mi komprenas vin tre bone.

Do you understand me? — Yes, I understand you very well.

English changes “speak” to “speaks” with a third-person singular subject and has highly irregular pairs such as “am/is/are.” Esperanto has neither pattern: mi estas, vi estas, ili estas. The pronoun or noun phrase identifies the subject.

Subjects are normally expressed when they refer to a person or thing. Esperanto is not generally a language that drops an understood “I,” “you,” or “they.” A subject can be absent with genuinely impersonal weather verbs and in second-person commands.

Pluvas, sed ni tamen promenos.

It is raining, but we will go for a walk anyway.

Fermu la fenestron, mi petas.

Close the window, please.

In pluvas, there is no hidden entity corresponding to English dummy “it.” In fermu, the understood addressee is built into the command situation. See expressing the subject for the full set of patterns.

Finite verbs and the infinitive

Forms in -as, -is, -os, -us, and -u can serve as the main verb of a clause. The infinitive in -i normally cannot carry an ordinary grammatical subject or independently assert a statement.

Ni volas foriri nun.

We want to leave now.

Foriri nun estus eraro.

Leaving now would be a mistake.

In the first example, finite volas anchors the clause and foriri names the wanted action. The understood doer of foriri is ni. In the second, the entire infinitive phrase foriri nun functions as the subject.

The infinitive remains a verb inside its phrase: it can take an object and other complements.

Ŝi volas aĉeti freŝan panon antaŭ la laboro.

She wants to buy fresh bread before work.

Here freŝan panon is the object of aĉeti, not of volas. Verb combinations therefore keep the valency—the pattern of objects and complements—of the meaningful verb. The dedicated infinitive in -i page develops this structure.

Do not build simple tenses with esti

English needs auxiliary forms of “be” for the progressive: “I am reading.” Esperanto normally expresses both “I read” and “I am reading” with the simple present mi legas. Likewise, mi legis can mean “I read,” “I was reading,” or “I have read,” depending on context.

Ne telefonu nun; mi kuiras.

Don't call now; I'm cooking.

Kiam vi telefonis, mi kuiris.

When you called, I was cooking.

Esperanto does possess compound forms with esti plus a participle, but they explicitly add a phase or result distinction and are often heavier than needed. They are not the default translation of every English auxiliary construction.

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Start with the simple form. Time words and context usually supply the distinctions for which English chooses “works,” “is working,” “has worked,” or “did work.” Use a compound participial form only when its extra aspectual precision matters.

Negatives and questions do not alter the verb

Place ne before the element being negated, normally the verb. Form a yes/no question with ĉu. Neither operation adds an auxiliary or changes the ending.

Mi ne konas ŝian adreson.

I don't know her address.

Ĉu ili venos hodiaŭ, aŭ ĉu ili venos morgaŭ?

Will they come today, or will they come tomorrow?

English inserts “do/does/did” in many negatives and questions. Esperanto has no comparable support auxiliary: Ĉu vi konas...?, not a translation built from “do.”

Endings do not decide valency

Changing tense or mood never changes which complements a verb licenses. A transitive verb such as legi continues to take an object in every form; an intransitive verb such as dormi does not acquire one merely because word order changes.

La infano legas la libron; hieraŭ ŝia frato legis ĝin.

The child is reading the book; yesterday her brother read it.

La bebo dormos en nia ĉambro ĉi-nokte.

The baby will sleep in our room tonight.

Case and prepositions identify each phrase's role. Free word order is not free valency: la libron la infano legas remains understandable because la libron is visibly the object.

Common Mistakes

Adding an English-style person ending

❌ Nun mi parolas, sed ŝi parolis ankaŭ.

Incorrect for the intended meaning 'she is speaking too' — -is is past, not a third-person ending.

✅ Nun mi parolas, kaj ŝi parolas ankaŭ.

Now I am speaking, and she is speaking too.

Using esti as a progressive auxiliary

❌ Mi estas legas la mesaĝon nun.

Incorrect — Esperanto uses the simple -as form for an action in progress.

✅ Mi legas la mesaĝon nun.

I am reading the message now.

Treating -us as a past ending

❌ Hieraŭ mi laborus ĝis la oka.

Incorrect for a factual past event — -us marks an imagined or conditional situation.

✅ Hieraŭ mi laboris ĝis la oka.

Yesterday I worked until eight.

Using the infinitive as an ordinary main verb

❌ Mi iri al la vendejo nun.

Incorrect — an ordinary assertion needs a finite verb.

✅ Mi iras al la vendejo nun.

I'm going to the shop now.

Confusing a command with the future

❌ Vi helpos min nun!

Incorrect if intended as a direct command — this predicts future help rather than grammatically requesting it.

✅ Helpu min nun!

Help me now!

Key Takeaways

The six invariant endings form one coherent system: -i, -as, -is, -os, -us, -u.
Only -as, -is, and -os directly contrast present, past, and future time.
Verbs never agree with the subject in person or number.
Simple forms normally cover English simple, progressive, and perfect-like readings; context supplies the precise interpretation.
Changing the ending changes tense or mood, not the verb's subject, object pattern, or other complements.

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