La patrino volas, ke la knabino restu hejme hodiaŭ.

In Esperanto, a comma is commonly used before ke when it introduces a subordinate clause. Here, ke la knabino restu hejme hodiaŭ is the content of what the mother wants, so it is set off with a comma.

So the structure is:

• La patrino volas = The mother wants
• ke la knabino restu hejme hodiaŭ = that the girl stay home today

The comma helps show the boundary between the main clause and the ke-clause.

Ke means that and introduces a clause.

In this sentence, it connects volas with the idea being wanted:

• La patrino volas = The mother wants
• ke la knabino restu hejme hodiaŭ = that the girl stay home today

This is very similar to English that, although English often omits that in everyday speech. Esperanto usually keeps ke.

Restu is used because this clause expresses a wish, will, intention, or desired action rather than a plain statement of fact.

Esperanto uses the -u verb ending for commands, requests, wishes, and similar ideas. After verbs like voli when one person wants someone else to do something, Esperanto often uses:

• voli, ke ... -u

So:

• La patrino volas, ke la knabino restu hejme. = The mother wants the girl to stay home.

Compare:

• restas = stays / is staying
• restos = will stay
• resti = to stay
• restu = stay / should stay / be to stay

Here restu is the correct form because it is not just describing what the girl does; it expresses what the mother wants her to do.

It is the -u form, which includes the imperative idea, but here it is not a direct command to the girl. Instead, it appears inside a ke-clause and expresses the mother’s wish or desire.

So:

• Restu hejme! = Stay home!
  This is a direct command.

But:

• La patrino volas, ke la knabino restu hejme. = The mother wants the girl to stay home.

That is not the speaker commanding the girl directly. It is reporting someone’s desire.

Because Esperanto normally uses ke + -u when the subject of the second verb is different from the subject of the first verb.

Here:

• La patrino is the subject of volas
• la knabino is the subject of restu

Since the subjects are different, Esperanto prefers:

• La patrino volas, ke la knabino restu hejme.

If the subject is the same, then Esperanto usually uses the infinitive:

• La patrino volas resti hejme. = The mother wants to stay home.

That is one of the most important patterns to learn:

• same subject -> voli + infinitive
• different subject -> voli, ke + -u

Because la knabino is the subject of restu, not the direct object of volas.

In the clause:

• ke la knabino restu hejme hodiaŭ

the girl is the one doing the staying, so she must be in the nominative form: la knabino.

Even though the whole clause is what the mother wants, inside that clause la knabino is still the subject of restu.

Hejme means at home.

Esperanto often uses the ending -e for adverbial location in certain common expressions, and hejme is the standard way to say at home.

Compare:

• hejmo = home, the home (a noun)
• hejme = at home
• hejmen = homeward / to home

So:

• restu hejme = stay at home
• iru hejmen = go home

Because the sentence means staying in that location, hejme is correct.

Hodiaŭ means today and tells when the staying should happen.

It modifies the idea of restu hejme:

• restu hejme hodiaŭ = stay home today

Esperanto word order is fairly flexible, so you could also see:

• La patrino volas, ke hodiaŭ la knabino restu hejme.
• La patrino volas, ke la knabino hodiaŭ restu hejme.

All are understandable, though the original sentence is very natural.

Volas is the present-tense form of voli, meaning to want.

Esperanto verb endings are regular:

• voli = to want
• volas = wants / is wanting
• volis = wanted
• volos = will want
• volu = want! / please want

So La patrino volas means The mother wants.

La is the definite article, meaning the.

So:

• la patrino = the mother
• la knabino = the girl

Esperanto has only one definite article, la, and it does not change for gender, number, or case.

Yes. English often omits that, but Esperanto usually keeps ke.

So these English translations are both natural:

• The mother wants that the girl stay home today.
• The mother wants the girl to stay home today.

But in Esperanto, the structure with different subjects is normally:

• La patrino volas, ke la knabino restu hejme hodiaŭ.

So even if English drops that or changes the structure, Esperanto still uses ke here.

It can feel like either, depending on context. The Esperanto -u form does not match one single English form perfectly.

In this sentence, restu expresses the mother’s desire, so English may translate it as:

• stay
• should stay
• is to stay

But the most natural translation is usually simply:

• The mother wants the girl to stay home today.

So restu carries the idea of intended or desired action, not a plain factual statement.