Adjectives

The adjective ending is -a:

• bela – beautiful
• granda frato – big brother
• malgranda fratino – little sister

💡 Memory aid: the final vowel signals the part of speech — -o for nouns, -a for adjectives, -e for adverbs (lesson 3).

Cases

Esperanto nouns have two cases, nominative and accusative. The accusative, marked by -n, shows the object of a transitive verb (the person or thing affected by the action):

• Kiun mi vidas? – Whom do I see?
• Mi vidas amikon. – I see a friend.

💡 Memory aid: English keeps a special object form in only a few pronouns — me, him, whom. Esperanto is consistent and marks every object with -n.

Do not use the accusative after the verb "to be" or its equivalents.

Adjectives agree with the nouns they qualify, taking the same -j and -n endings:

• Vi estas bona amiko. – You're a good friend.
• Vi estas bonaj amikoj. – You're good friends.
• Vi havas bonan amikon. – You have a good friend.
• Vi havas bonajn amikojn. – You have good friends.

Esperanto expresses other case relationships with prepositions. The English possessive ('s) is rendered by de ("of"):

• La libroj de mia frato. – My brother's books.

Conjugation

To conjugate, simply replace the infinitive -i with the tense ending. The ending is the same for every person, and there are no irregular verbs.

Base form: -i

• labori – to work

Present tense: -as

• mi laboras – I work
• vi laboras – you work
• li/ŝi laboras – he/she works
• ni laboras – we work
• ili laboras – they work

Past tense: -is

• mi laboris – I worked
• vi laboris – you worked
• li/ŝi laboris – he/she worked
• ni laboris – we worked
• ili laboris – they worked

Future tense: -os

• mi laboros – I will work
• vi laboros – you will work
• li/ŝi laboros – he/she will work
• ni laboros – we will work
• ili laboros – they will work

💡 Memory aid: the tense vowels run i–a–o:

• -is (past)
• -as (present)
• -os (future)

The conjunction ke

introduces a noun clause. Unlike its English equivalent "that":

1. it can never be omitted, and
2. it is usually preceded by a comma.

• Vi vidas, ke mi manĝas. – You see that I'm eating.
• Li diras, ke li iros. – He says he'll go.

⚠️ Watch out: don't confuse ke ("that", a conjunction) with kio ("what", a question word). ke only links clauses and asks nothing.

The prefix mal-

changes a word to its exact opposite:

• bona – good / malbona – bad
• granda – big, great / malgranda – little, small
• bela – beautiful / malbela – ugly

💡 Memory aid: you already know mal- from English words like malfunction and malformed. One prefix saves learning a separate word for every opposite.

The prefix ge-

denotes both sexes together:

• gefratoj – brothers and sisters
• gepatroj – parents

Polite expressions

• bonvolu – please, be so good as to
• dankon – thank you
• saluton – hello, hi

Word order

The usual order is subject–verb–object, as in English. But because the accusative -n shows which word is the object, word order can be varied far more freely than in English — for emphasis or style:

• Mi legas libron. – I'm reading a book.
• Libron mi legas. – (A book is what I'm reading.)

Kio, Kion

kio means "what" as the subject of the sentence:

• Kio estas tio? – What's that?
• Kio estas sur la tablo? – What is on the table?

When "what" is the object of the verb, the Esperanto equivalent takes the accusative, kion:

• Kion vi faras? – What are you doing?
• Kion ŝi diris? – What did she say?