Ni kune organizas la festivalon.

• Ni = we
• kune = together
• organizas = organize / are organizing
• la = the
• festivalon = festival as the direct object

So grammatically, it is:

subject + adverb + verb + object

In Esperanto, words ending in -e are usually adverbs. Adverbs describe how, when, where, or in what way something happens.

So kune means together, and it describes how we organize the festival.

Compare:

• bona = good
• bone = well

Similarly:

• kun = with
• kune = together

The ending -as marks the present tense in Esperanto.

So:

• organizas = organize / are organizing
• organizis = organized
• organizos = will organize
• organizu = organize! / let ... organize
• organizi = to organize

Esperanto verbs do not change based on the subject:

• mi organizas = I organize
• ni organizas = we organize
• ili organizas = they organize

The -n shows the direct object. That is, it marks the thing directly affected by the verb.

In this sentence, the festival is what we organize, so it takes -n:

• la festivalo = the festival
• la festivalon = the festival as the object

This is called the accusative ending.

La means the. Esperanto has a definite article, but unlike English, it has only one form: la.

So:

• festivalo = festival / a festival
• la festivalo = the festival

Esperanto has no word for a/an. If you just say festivalo, it can mean a festival or simply festival, depending on context.

Because la never changes. It is always just la.

The noun changes:

• la festivalo
• la festivalon

But the article stays the same:

• la

This is much simpler than in many European languages.

Not completely. Esperanto word order is fairly flexible, especially because the -n ending shows the object clearly.

The most neutral order is:

Ni kune organizas la festivalon.

But you could also say:

• Ni organizas kune la festivalon.
• La festivalon ni kune organizas.

These are grammatically possible, though they may sound more marked or emphasize a different part of the sentence.

For learners, the basic word order subject + verb + object is the safest default.

Yes. Adverbs in Esperanto can often move around.

All of these are possible:

• Ni kune organizas la festivalon.
• Ni organizas kune la festivalon.
• Kune ni organizas la festivalon.

The meaning stays very similar, but the emphasis can shift slightly:

• Kune ni... can emphasize together
• Ni kune... is very natural and neutral

Normally, you should include ni.

Esperanto verbs do not show person or number the way Spanish or French verbs do. Organizas could mean:

• I organize
• you organize
• we organize
• they organize

So the subject pronoun is usually needed:

• mi organizas
• vi organizas
• ni organizas

Without ni, the sentence would be incomplete unless the subject were already very clear from context.

Because festivalon is singular.

• -o = noun
• -j = plural
• -n = accusative

So:

• festivalo = festival
• festivaloj = festivals
• festivalon = festival as object
• festivalojn = festivals as object

Since this sentence talks about one festival, it uses festivalon.

Either can be correct, depending on context.

Esperanto -as is a general present tense. It can correspond to:

• organize
• are organizing
• sometimes even do organize

So Ni kune organizas la festivalon could mean:

• We organize the festival together
• We are organizing the festival together

The surrounding context tells you which English version sounds best.

They are related, but they are used differently.

• kun = with
  This is a preposition.

  • Mi venas kun vi. = I am coming with you.

• kune = together
  This is an adverb.

  • Ni laboras kune. = We work together.

In your sentence, kune is correct because it describes how the organizing happens.

Esperanto pronunciation is very regular. Organizas is pronounced roughly like:

or-ga-NI-zas

A few helpful points:

• every vowel is pronounced clearly
• stress usually falls on the second-to-last syllable
• so in organizas, the stress is on ni

Broken into syllables: or-ga-ni-zas

The same stress rule works for most Esperanto words:

• fes-ti-VA-lon
• KU-ne
• NI