La katido ludas kun ludilo.

La is the definite article in Esperanto, like the in English.

So la katido means the kitten, not just a kitten.

A few useful things about la:

• It never changes form.
• It is used for singular and plural:
  • la katido = the kitten
  • la katidoj = the kittens
• Esperanto has no indefinite article. So katido by itself can mean a kitten or just kitten, depending on context.

It is built very regularly from parts:

• kat- = cat
• -id- = offspring / young one
• -o = noun ending

So:

• kato = cat
• katido = kitten

This is a very common feature of Esperanto: words are often made from a root plus affixes.

More examples of -id-:

• hundo = dog
• hundido = puppy

So katido is not an irregular special word you just have to memorize; it follows a pattern.

In Esperanto, all present-tense verbs end in -as.

So:

• ludi = to play
• ludas = plays / is playing / play

Esperanto does not change the verb ending depending on the subject. That means:

• mi ludas = I play
• vi ludas = you play
• la katido ludas = the kitten plays
• ili ludas = they play

Other common verb endings are:

• -is = past
• -os = future
• -us = conditional
• -u = command / wish
• -i = infinitive

Because Esperanto -as covers the general present tense.

So ludas can mean:

• plays
• is playing
• sometimes even does play, depending on context

Usually the surrounding context makes the meaning clear. Esperanto often relies on simple, regular verb forms instead of having many different tense constructions like English.

Kun is a preposition meaning with.

So kun ludilo means with a toy.

It links the action to something accompanying it. In this sentence, the kitten is playing with a toy.

Like English prepositions, Esperanto prepositions are very common and important to learn as fixed words:

• kun = with
• en = in
• sur = on
• sub = under
• al = to

Ludilo is also built from parts:

• lud- = play
• -il- = tool / instrument
• -o = noun

So ludilo literally means something like a play-tool, which in normal English is a toy.

This is another very typical Esperanto word-building pattern.

Compare:

• tranĉi = to cut

• tranĉilo = a cutting tool = knife

• skribi = to write
• skribilo = a writing tool

So ludilo is a very transparent, logical word once you know the pieces.

Because ludilo here is the object of the preposition kun, not the direct object of the verb.

In Esperanto, the -n ending usually marks the direct object:

• La katido vidas la ludilon. = The kitten sees the toy.

But after a preposition like kun, you normally do not add -n:

• kun ludilo = with a toy

So in this sentence:

• La katido = subject
• ludas = verb
• kun ludilo = prepositional phrase

That is why ludilo stays without -n.

Sometimes learners wonder about that, because both can be translated as with in English.

• kun = with, together with, in the company of
• per = by means of, using

In this sentence, kun ludilo is natural for playing with a toy.

If you used per ludilo, it would sound more like by means of a toy or using a toy as an instrument, which is less natural here.

So for a kitten playing and a toy accompanying the action, kun is the better choice.

Because -o is the standard noun ending in Esperanto.

That means both words are nouns:

• katido = kitten
• ludilo = toy

This is one of the basic parts of Esperanto grammar:

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

For example:

• katido = kitten
• katida = kitten-related / kitten-like
• lude would be an adverb based on play, though less common in everyday use
• ludi = to play

This regular system helps you identify the role of a word quickly.

Yes, Esperanto word order is fairly flexible, because endings make the grammar clear.

The normal, neutral order here is:

• La katido ludas kun ludilo.

But other orders are possible for emphasis or style, such as:

• Kun ludilo la katido ludas.

That still means basically the same thing, though it may sound more marked or literary.

For beginners, it is usually best to stick to the most neutral order:

subject + verb + other information

So this sentence is a good standard model.

Esperanto spelling is very regular, and each letter has a consistent sound.

A rough pronunciation guide:

• La ≈ lah
• katido ≈ kah-TEE-doh
• ludas ≈ LOO-dahs
• kun ≈ koon
• ludilo ≈ loo-DEE-loh

Stress in Esperanto normally falls on the second-to-last syllable:

• kaTIdo
• LUdas
• luDIlo

So the full sentence is roughly:

lah kah-TEE-doh LOO-dahs koon loo-DEE-loh

You would make katido plural by adding -j:

• La katidoj ludas kun ludilo.

Breakdown:

• katido = kitten
• katidoj = kittens

The verb stays the same:

• ludas for both singular and plural

That is another nice feature of Esperanto: verbs do not change depending on number or person.

You could also say:

• La katidoj ludas kun ludiloj. = The kittens play with toys.

There, both nouns are plural:

• katidoj = kittens
• ludiloj = toys