La lifto ne funkcias, tial ni uzas la ŝtuparon.

Because la ŝtuparon is the direct object of uzas.

• uzi = to use
• what do we use? la ŝtuparon

In Esperanto, direct objects usually take -n. This is called the accusative ending.

So:

• la ŝtuparo = the staircase / the stairs
• ni uzas la ŝtuparon = we use the staircase / stairs

The -n here does not mean motion toward something. It is simply marking the object of the verb.

La is the definite article, meaning the.

It is used here because the sentence is talking about specific things that the speaker and listener can identify from the situation:

• la lifto = the elevator in this building
• la ŝtuparon = the staircase / the stairs here

Esperanto has:

• la = the
• no separate word for a/an

So:

• lifto can mean an elevator or just elevator
• la lifto means the elevator

Tial means therefore, for that reason, or that’s why.

It connects the first idea to the result:

• La lifto ne funkcias = the elevator is not working
• tial ni uzas la ŝtuparon = therefore / so we use the stairs

It is one of the ti- words in Esperanto:

• tio = that
• tial = for that reason
• tiam = then
• tie = there

A very literal way to think of tial is for that reason.

Funkcii means to function, to operate, or to work for a machine or system.

So La lifto ne funkcias means the elevator is not functioning.

This is very natural for machines, devices, systems, and services. A learner might think of labori, but labori usually means to work in the sense of doing labor or having a job. For a machine, funkcii is usually the better choice.

Examples:

• La komputilo ne funkcias. = The computer is not working.
• La telefono funkcias bone. = The phone works well.

Yes, lifto is widely used and easy to understand.

You may also see elevilo, which is more transparently built from Esperanto roots and can also mean lift/elevator.

So both can appear, depending on style:

• lifto
• elevilo

In everyday use, lifto is very common.

They are related, but not the same:

• ŝtupo = a single step
• ŝtuparo = a staircase, stairway, or set of stairs

The ending -ar- is a useful Esperanto suffix meaning a collection or group of things.

So:

• arbo = tree
• arbaro = forest

Likewise:

• ŝtupo = step
• ŝtuparo = a whole staircase / stairs

That is why the sentence uses ŝtuparon, not ŝtupon. We are using the stairs as a whole, not one individual step.

Because the sentence describes a present situation:

• the elevator is not working now
• as a result, we use the stairs now

Esperanto present tense often covers what English expresses with either the simple present or the present progressive.

So ni uzas can correspond to:

• we use
• we are using

The exact English translation depends on context, but the Esperanto present tense is perfectly normal here.

Yes, to some extent.

The original sentence is very natural:

• La lifto ne funkcias, tial ni uzas la ŝtuparon.

You could also say:

• La lifto ne funkcias; tial ni uzas la ŝtuparon.
• La lifto ne funkcias. Tial ni uzas la ŝtuparon.

Because Esperanto marks the direct object with -n, word order is somewhat flexible. But in ordinary speech and writing, the most neutral order is still:

• subject + verb + object

So ni uzas la ŝtuparon is the most straightforward form.

Normally, no.

Esperanto usually states the subject explicitly:

• mi = I
• vi = you
• li/ŝi/ĝi = he/she/it
• ni = we

So ni uzas la ŝtuparon is the normal way to say we use the stairs.

Leaving out the subject would sound incomplete in a standard sentence, unless the context is very unusual, such as notes, commands, or special stylistic usage.

A rough pronunciation guide:

• lifto → LIF-to
• funkcias → funk-CI-as
• tial → TI-al
• ŝtuparon → ŝtu-PA-ron

A few helpful points:

• ŝ sounds like English sh
• stress in Esperanto is almost always on the second-to-last syllable
• each vowel is pronounced clearly

So:

• tial has two clear vowel sounds: ti-al
• funkcias is not compressed into one syllable at the end; it is ci-as

It can mean either, depending on context and translation style.

Esperanto ŝtuparo refers to the staircase or stairway as a whole. In natural English, that is often translated simply as the stairs.

So both of these are reasonable translations:

• we use the staircase
• we use the stairs

English usually prefers the stairs in everyday speech, but Esperanto ŝtuparo itself is singular in form.