Esperanto Verb Tenses and Conjugation: -as, -is, -os

Drop the -i from the infinitive and add one of five endings. The ending never changes for the person, and no verb is irregular. That is the entire Esperanto verb system.

The whole system on one screen

The root est- never changes. Watch one verb go through every tense:

Each tense in a sentence:

• Mi vidas lin nun. - I see him now.
• Mi vidis lin. - I saw him.
• Mi vidos lin. - I will see him.
• Mi vidus lin, se mi povus. - I would see him, if I could.
• Vidu! - Look! (literally: see!)

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1. 1Hieraŭ mi ludis.
2. 2Hodiaŭ mi legas.
3. 3Morgaŭ mi iros per biciklo.

Yesterday, today, tomorrow: the root stays put and only the ending moves, -is, -as, -os.

One form for every person

The ending is the same whoever does the action:

English needs am, is and are for this column; French needs six forms, irregularly. In Esperanto the pronoun already says who, so the verb does not repeat it.

Because the verb does not say who, the subject pronoun stays in the sentence: Mi estas tie. is I am there, and Estas tie on its own does not say who is. Two kinds of sentence have no subject to say:

• Pluvas. - It is raining. (weather has no it)
• Venu! - Come! (the vi is understood)

No irregular verbs, not even to be

To be is irregular in almost every language. English be has eight shapes: be, am, is, are, was, were, being, been. Esperanto's has six forms, and each is the root plus the ending you would have predicted. Every other verb works the same way:

You could have generated every cell yourself. That is the point. (scii looks odd with its double i, but the root is sci-: ŝi scias, she knows.)

One present, one past: no continuous to learn

-as covers both English presents, and -is both pasts:

• Mi parolas. - I speak. / I am speaking.
• Ŝi legis. - She read. / She was reading.

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1. 1Ŝi legas.
2. 2Li kuiras.
3. 3Li kuras.
4. 4Ŝi parolas per telefono.

Each of them is doing it right now, and plain -as says so: she is reading, he is cooking, he is running, she is on the phone.

There is no am speaking form to build. Mi estas paroli is not Esperanto, and the participle forms (mi estis parolanta) are rare and heavy: plain -as and -is are the natural choice.

When to use -u

-u has no single English counterpart. It does three jobs:

The third catches English speakers. After ke, when someone wants a new subject to do something, the verb takes -u:

• Mi volas, ke vi venu. - I want you to come.
• Mi volas veni. - I want to come.

With no new subject, as in the second line, the infinitive -i stays. The full story is in the conditional and commands.

When to use -us

-us is the would ending, and it goes on both halves of an if-sentence:

• Se mi povus, mi farus tion. - If I could, I would do that.

English changes the verb in one half (could) and adds a helper in the other (would do). Esperanto puts -us on both.

Mistakes English speakers make

What to do next

1. Take one verb you know and say all six forms aloud.
2. Write three sentences about yesterday, today and tomorrow with the same verb.
3. Then read the accusative: the -n that marks the object.

See also

• Word endings - the -o, -a, -e and -i that come first.
• The conditional and commands - -us and -u in full.
• Participles - the -ant-, -int-, -ont- forms that carry tense into adjectives.
• Compound tenses - what esti plus a participle adds, and why you rarely need it.