La kato tuj kuŝas sur la tapiŝo, ĉar ĝi estas pli mola ol la malnova seĝo.

La is the Esperanto definite article, equivalent to English the. It is used for specific things: la kato, la tapiŝo, and la malnova seĝo.

A useful point for English speakers: Esperanto has only one article, la. It does not change for singular/plural, gender, or case.

Tuj means immediately, right away, or at once.

It is placed before kuŝas to show that the cat lies down or is lying there immediately. Esperanto word order is fairly flexible, but putting tuj before the verb is very natural.

The verb kuŝi means to lie, to be lying, or to be in a lying position. It is used for someone or something resting horizontally.

So with a cat on a carpet, kuŝas is a very natural choice.

For an English speaker, it helps to notice that Esperanto often distinguishes:

• sidi = to sit
• stari = to stand
• kuŝi = to lie

Strictly speaking, kuŝas describes the state: is lying or lies.

If you want to emphasize the change into that position, Esperanto often uses kuŝiĝas, meaning lies down or gets into a lying position.

So in this sentence, kuŝas focuses more on the cat being in that position. In everyday usage, though, context can make it feel close to English lies down.

Because this phrase shows location, not movement toward a destination.

In Esperanto, prepositions like sur can be followed by:

• no -n ending for location: sur la tapiŝo = on the carpet
• an -n ending for direction/motion onto something: sur la tapiŝon = onto the carpet

Here the cat is described as lying on the carpet, so sur la tapiŝo is correct.

Ĉar means because. It introduces the reason: the cat is on the carpet because it is softer than the old chair.

It works much like English because, and it introduces a subordinate clause.

Most likely, ĝi refers to la tapiŝo.

So the idea is that the cat chooses the carpet because the carpet is softer than the old chair.

However, this sentence is a little potentially ambiguous, because ĝi could in theory point to another neuter thing in the context. If you wanted to make it completely clear, you could say ĉar la tapiŝo estas pli mola ol la malnova seĝo.

This is the standard Esperanto pattern for comparisons:

pli + adjective + ol

So:

• mola = soft
• pli mola = softer
• pli mola ol la malnova seĝo = softer than the old chair

This is very regular in Esperanto:

• pli granda ol = bigger than
• pli rapida ol = faster than
• pli interesa ol = more interesting than

Because they are adjectives.

In Esperanto:

• nouns end in -o
• adjectives end in -a
• adverbs end in -e

So:

• tapiŝo = carpet
• seĝo = chair
• mola = soft
• malnova = old

Adjectives also agree with the nouns they describe. Here both nouns are singular and not accusative, so the adjectives stay in the basic form:

• mola
• malnova

Because Esperanto often builds words from opposites very systematically.

• nova = new
• mal- = opposite
• malnova = old

This is one of the most common patterns in Esperanto. English speakers often notice it quickly because it is very productive:

• bona = good
• malbona = bad
• fermita = closed
• malfermita = open

So malnova seĝo literally means something like not-new chair, which in normal English is simply old chair.

The ending -as marks the present tense in Esperanto.

So kuŝas can mean lies, is lying, or sometimes a present-tense action in a narrative style. Esperanto present tense is often broader than a single English form, so context tells you whether it feels more like:

• lies
• is lying
• lies down in a looser, contextual sense

That is why one Esperanto form may correspond to more than one natural English translation.