La kaĝo estas pura.

In Esperanto, nouns normally end in -o. So kaĝo is clearly a noun.

This is one of the most useful patterns in the language:

• -o = noun
• -a = adjective
• -e = adverb
• -i = infinitive verb

So when you see kaĝo, you can immediately recognize it as a noun: cage.

La is the definite article, meaning the.

So:

• la kaĝo = the cage

Unlike English, Esperanto has only one article like this:

• no separate form for a/an
• la never changes for gender, number, or case in form

So whether the noun is singular or plural, la stays la.

Because pura is an adjective, and Esperanto adjectives normally end in -a.

So:

• pura = clean

This lets you recognize it immediately as a describing word.

Because this sentence has no direct object.

In La kaĝo estas pura, pura is not an object. It is a predicate adjective, describing the subject la kaĝo after the verb estas.

So:

• la kaĝo = subject
• estas = linking verb
• pura = description of the subject

In normal Esperanto, you do not add -n to a predicate adjective after esti.

So:

• La kaĝo estas pura. = correct

In Esperanto, verbs do not change according to person or number.

Estas is the present tense form of esti (to be), and it stays the same with all subjects:

• mi estas = I am
• vi estas = you are
• li estas = he is
• ŝi estas = she is
• ĝi estas = it is
• ili estas = they are

So La kaĝo estas pura uses estas simply because the sentence is in the present tense.

The special letter ĝ is pronounced roughly like the j in judge or jam.

So kaĝo is pronounced approximately KAH-zho or KAH-jo, with the middle sound like English j but often described with a zh/j quality depending on how it is explained.

A rough pronunciation of the whole sentence is:

• lah KAH-zho EHS-tahs POO-rah

Also remember that Esperanto stress usually falls on the second-to-last syllable:

• KA-ĝo
• ES-tas
• PU-ra

Yes. Adjectives in Esperanto agree with the nouns they describe in number and accusative case.

That means:

• singular adjective: -a
• plural adjective: -aj
• accusative singular adjective: -an
• accusative plural adjective: -ajn

Here, kaĝo is singular and not accusative, so the adjective is also singular and not accusative:

• la kaĝo estas pura

If it were plural, you would get:

• La kaĝoj estas puraj. = The cages are clean.

Because there is no direct object.

The ending -n is usually used for:

• the direct object
• sometimes motion toward something

In this sentence:

• la kaĝo is the subject
• pura describes the subject
• estas is a linking verb

So no word needs -n here.

The normal word order here is:

• subject + verb + adjective/complement

So:

• La kaĝo estas pura.

That is the most natural and neutral order.

Esperanto word order is fairly flexible, but this standard order is what learners should use first. Changing it is possible for emphasis or style, but it is not necessary here.

Yes, you could, but it would change the meaning.

• La kaĝo estas pura. = The cage is clean.
• Kaĝo estas pura. = A cage is clean or Cage is clean, depending on context

Without la, the noun is indefinite or more general. In most ordinary situations, if you mean one specific cage already known in context, la is the right choice.

Because here pura is not directly attached to the noun inside a noun phrase. It comes after estas and works as a predicate adjective.

Compare:

• La kaĝo estas pura. = The cage is clean.
• La pura kaĝo = the clean cage

In the first sentence, pura tells you the state of the cage. In the second, pura is directly modifying kaĝo as part of the noun phrase.

It is a simple copular sentence: a sentence using esti (to be) to link the subject to a description.

Structure:

• La kaĝo = subject
• estas = linking verb
• pura = subject complement / predicate adjective

This pattern is extremely common in Esperanto, just as in English:

• La domo estas granda. = The house is big.
• La akvo estas malvarma. = The water is cold.

Usually it means clean or pure, depending on context.

In a sentence like La kaĝo estas pura, the most natural interpretation is physical cleanliness: the cage is clean.

But in other contexts, pura can also mean things like:

• pure
• unmixed
• morally clean, depending on usage

So the exact nuance depends on what is being described.