Esperanto -us and -u: Conditional and Imperative

-us says what would happen; -u says what somebody wants to happen. Neither ending changes for person or tense, and both go on the verb root like any other ending.

-us goes on both halves

English marks an unreal sentence twice, with two different tools: a past tense in the if half and would in the other. Esperanto uses one ending, twice:

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

Do not copy the English past into the if half. Se mi havis tempon is a real past: whenever I had time, back then.

• Se mi havis tempon, mi legis. - If (whenever) I had time, I read.

kvazaŭ: as if

Kvazaŭ introduces something imagined, so it normally takes -us as well:

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

Open conditions keep their tense

-us is for a condition that is contrary to fact or unlikely. One that may well come true takes the ordinary tense, in both halves:

The first row is the one to notice. English says if you come, present, about the future; Esperanto says venos, because the coming is in the future. The third row is a plain general truth, so it takes the present.

-us has no tense

There is no past conditional ending. The same sentence covers now and then:

• Se mi scius, mi dirus al vi. - If I knew, I would tell you. / If I had known, I would have told you.

Context settles it, or an adverb such as tiam (then):

• Se mi tiam scius, mi dirus al vi. - If I had known then, I would have told you.

When the past must be explicit, estus plus an -inta participle does it: mi estus dirinta al vi, I would have told you. It is correct and heavy; compound tenses has the full set.

-u: the command

The Fundamento calls -u the imperative (ordona modo). Many later grammars call it the volitive (from voli, to want), because it marks any action somebody wants to happen, not only an order. The plain command is the commonest case:

There is no do to add in a negative command: ne goes in front and that is all. The bare form is the neutral command; stating vi points a finger.

1234

1. 1Sidiĝu!
2. 2Malfermu la libron!
3. 3Ne kuru!
4. 4Silentu!

Sidiĝu! Sit down! Malfermu la libron! Open the book! Ne kuru! Do not run! Silentu! Be quiet! Every one is the root plus -u.

Ni iru, li venu, kion mi faru?

-u works with every person, which gives Esperanto one form for what English does with let, should and shall:

Kion mi faru? asks what you are wanted to do. Kion mi devas fari? (what must I do?) is also correct, but it asks what is obligatory, which is a slightly different question.

From blunt to polite

A request can be a bare command, a bonvolu, or a polite -us question. The strip runs from blunt to soft:

Bonvolu is itself a -u form: bonvoli is to be so kind as to, and the infinitive follows it. Mi volas paroli kun vi is not rude, but it lands like I want a word; mi volus is I'd like a word.

After ke: -u for what someone wants

When the main verb wants, asks, orders, permits or requires something, and someone new is to do it, the ke clause takes -u:

English uses an infinitive with its own subject (you to come), which is why learners write ke vi veni. That is not Esperanto. Some verbs of asking and ordering also allow the person plus an infinitive:

• Li petis min resti. - He asked me to stay.

Voli never does: I want you to come is always the ke clause.

Three more points:

• -u has no tense: Mi volis, ke li venu. - I wanted him to come.
• Por ke (so that) takes -u: Mi laboras, por ke miaj infanoj lernu. - I work so that my children learn.
• With the same subject, por takes the infinitive: Mi laboras por vivi. - I work to live.

Report or demand?

-u follows verbs of wanting, not verbs of saying or knowing. A report keeps the real tense. Diri can do either job, so the ending alone tells you which:

The ke clause keeps the tense of what was true at the moment of the main verb: when she was thought to be there, she is there, so estas. Reported speech has the whole rule.

When English would is not -us

English would also reports a future from a past moment: he said he would come. Esperanto uses -os there, because at the moment of saying, the coming was still ahead:

• Li diris, ke li venos. - He said he would come.
• Li diris, ke li venus, se li povus. - He said he would come if he could.

Mistakes English speakers make

What to do next

1. Say three things you would do if you had a free day, with -us in both halves.
2. Turn each into a request with ĉu vi povus and then with bonvolu.
3. Then read subordinate clauses for the rest of what ke does.

See also

• Verb tenses - -us and -u alongside -as, -is and -os.
• Subordinate clauses - ke clauses, where the choice between -u and a tense is made.
• Reported speech - why he said he would come is li diris, ke li venos.
• Compound tenses - mi estus dirinta, for when the past must be explicit.
• Letter writing and register - mi volus and ĉu vi povus in polite writing.