Numerals

The numerals are listed in the appendix. Higher numbers are formed by combining the basic numerals:

• 1 238 – mil du-cent tri-dek ok
• 153 837 – cent kvin-dek tri mil ok-cent tri-dek sep
• Addition: 8 + 3 = 11 – ok plus tri estas dek-unu
• Subtraction: 15 - 6 = 9 – dek-kvin minus ses estas naŭ

Accusative of Motion Towards

Esperanto prepositions are normally followed by the nominative:

• post mi – after me
• sen ŝi – without her
• en domo – in a house

But a preposition of place may take the accusative -n to show motion toward something:

• Mi iras en la domon. – I am going into the house.
  • (Compare: Ili manĝas en la domo. – They are eating in the house.)
• La kato saltis sur la tablon. – The cat jumped onto the table.
  • (Compare: La kato saltis sur la tablo. – The cat jumped around on the table.)

💡 Memory aid: the -n is exactly the difference between English "in" and "into", "on" and "onto": no -n = where (location), -n = where to (motion). en la domo = in the house, en la domon = into the house.

The pronoun oni

The indefinite pronoun oni means "people (in general)", "they", or "you" (in the general sense):

• Oni manĝas. – People are eating.
• Oni sidas. – People are sitting.

💡 Memory aid: oni matches the English impersonal "one" — and conveniently even looks like it.

The reflexive pronoun si

si (accusative sin) refers back to the subject of the clause — himself, herself, itself, themselves, oneself:

• Li lavas sin. – He washes himself.
• Ŝi rigardas sin. – She looks at herself.
• Ili kantas al si. – They are singing to themselves.

si is used only for a third-person subject, and is never itself the subject of a sentence. Compare:

• Mi rigardas min. – I look at myself.
• Ili rigardas sin. – They look at themselves.

Time and direction questions

Kiam asks "when". Kie asks "where". Kien asks "where to". The ending -n in kien shows direction:

• Kiam vi venos? – When will you come?
• Kie vi estas? – Where are you?
• Kien vi iros? – Where will you go?

For duration, use kiom longe:

• Kiom longe vi sidas? – How long are you sitting?

Clauses with kiam and se

Kiam and se can begin a small clause:

• kiam estas varme – when it is warm
• se vi venos – if you come

The prefix re-

Like English "re-", it can mean either "again, a second time" or "back":

• refari – to do again
• redoni – to give back
• remeti – to put back, to replace

En and el in longer words

En and el can stand at the beginning of a verb. En points inward; el points outward:

• en + iri → eniri – to go in
• el + iri → eliri – to go out
• el + veni → elveni – to come out