Mi vidas lin ĉe la stacidomo.

Because lin is the direct object form of the pronoun.

• li = he
• lin = him

In this sentence, mi is the one doing the action, and lin is the person being seen, so Esperanto uses lin.

Here, -n marks the direct object: the person or thing directly affected by the verb.

So in Mi vidas lin:

• mi = subject
• vidas = verb
• lin = direct object

This is one of the most important endings in Esperanto. It often lets Esperanto keep meanings clear even if the word order changes.

Esperanto verbs have very regular endings. The ending -as means present tense.

• vid- = the verb root, see
• -as = present tense

So vidas means see / sees / am seeing, depending on context.

Unlike English, Esperanto does not change the verb depending on the subject:

• mi vidas = I see
• li vidas = he sees
• ili vidas = they see

The verb form stays vidas.

Because Esperanto usually uses the simple present -as for both:

• I see
• I am seeing

So Mi vidas lin can work naturally where English might say either I see him or I am seeing him, depending on the situation.

There are more explicit progressive-style forms, but they are much less common in ordinary speech.

ĉe usually means something like at, by, or near a place.

So ĉe la stacidomo suggests being at the station, by the station, or in the station area, without necessarily saying someone is physically inside the building.

By contrast:

• en la stacidomo = in the station, inside the station

So the choice between ĉe and en depends on whether you mean general location or being inside.

It is a compound word.

• stacio = station
• domo = house/building

In compounds, Esperanto often combines roots directly:

• staci-
  • dom-
    • -o = stacidomo

So stacidomo is literally something like station-building, which is the normal Esperanto word for a railway station.

This is very common in Esperanto: many words are built from smaller meaningful parts.

La is the definite article, equivalent to English the.

So la stacidomo = the station

A few useful things about la:

• it never changes form
• it does not show gender
• it does not show number
• it does not take special endings here

Esperanto has one definite article: la.

Yes, more easily than in English, because the -n on lin shows that it is the object.

The neutral order is:

• Mi vidas lin ĉe la stacidomo.

But you could also say:

• Lin mi vidas ĉe la stacidomo.
• Ĉe la stacidomo mi vidas lin.

These are still understandable, though they may sound more emphatic or marked. For learners, the basic subject–verb–object order is the safest default.

Ĉ is pronounced like English ch in church.

So ĉe sounds roughly like cheh.

If you cannot type ĉ, Esperanto learners sometimes write che as a rough guide, or cxe in the x-system, but the normal spelling is ĉe.

In Esperanto, the stress is always on the second-to-last syllable.

So:

• MI
• VI-das
• LIN
• ĈE
• sta-ci-DO-mo

A rough pronunciation of the full sentence is:

mee VEE-dahs leen cheh stah-tsee-DOH-moh

You would replace lin with ŝin.

• li / lin = he / him
• ŝi / ŝin = she / her

So:

• Mi vidas ŝin ĉe la stacidomo.

The rest of the sentence stays the same.