Pasporto eksvalidiĝos post la vizo.

It means will expire or will become no longer valid.

A useful way to see it is:

• valid- = valid
• -iĝ- = become, get into a state
• -os = future tense

So validiĝos would be will become valid, and eksvalidiĝos adds the idea that the validity ends, so the whole word means will expire / will cease to be valid.

Esperanto often packs a whole English phrase into one word like this.

The suffix -iĝ- shows that the subject undergoes a change of state.

So:

• eksvalidiĝi = to expire, to become invalid
• eksvalidigi = to make something expire, to invalidate something

In this sentence, the passport itself is the thing that changes status, so -iĝ- is the natural choice.

Because the verb ends in -os, which is the Esperanto future tense.

Some basic tense endings are:

• -as = present
• -is = past
• -os = future

So eksvalidiĝos means will expire, not expires or expired.

Esperanto has no indefinite article. English uses a/an, but Esperanto does not.

So:

• pasporto can mean a passport
• depending on context, it can also be understood as the passport

Esperanto only has one article, la, which means the.

Because la is only used when the noun is definite: when the speaker assumes the listener can identify it.

So la vizo means the visa.

As for pasporto, leaving out la can make it more general or leave the definiteness to context. In a fuller context, many speakers might also say la pasporto if they mean one specific passport.

So this contrast is not strange in Esperanto:

• pasporto = a passport / the passport, depending on context
• la vizo = the visa, specifically identified

Because post is a preposition, and normally nouns after prepositions do not take the accusative -n.

So:

• post la vizo = after the visa

The -n ending is mainly used for:

• direct objects
• direction in some expressions
• certain time/measure uses

Here, la vizo is just the object of the preposition post, so plain vizo is correct.

It is a slightly compact way of speaking. In context, it usually means something like:

• after the visa expires
• after the visa’s period of validity
• later than the visa

A fuller version could be something like post la eksvalidiĝo de la vizo.

But Esperanto, like English, often allows a shorter phrase when the intended meaning is obvious from context.

No. Esperanto word order is fairly flexible, because grammar is shown mostly by endings and particles, not by position alone.

This sentence could also appear as:

• Post la vizo pasporto eksvalidiĝos.
• La pasporto eksvalidiĝos post la vizo.

The most neutral order is often subject–verb–other information, as in the original sentence, but changing the order can shift emphasis.

Yes, depending on style and context.

Eksvalidiĝi is a very natural choice for documents, permits, visas, passports, memberships, and similar things, because it literally means to cease being valid.

You may also see related expressions, but eksvalidiĝi is especially precise in administrative or legal contexts. It is a good verb to learn for documents and official validity periods.

Yes, in this sentence post is temporal: after in time.

Esperanto post can also be spatial in other contexts, meaning behind or after in sequence, but here the future tense and the idea of document validity make the time meaning clear.