Eksvalidiĝinta pasporto malhelpas la vojaĝon.

It means expired or that has expired.

It is the adjective form of eksvalidiĝi, meaning to expire / to cease to be valid. A rough breakdown is:

• valid- = valid
• eks- = no longer / ex-
• -iĝ- = become
• -int- = having already done/undergone the action
• -a = adjective ending

So eksvalidiĝinta pasporto means an expired passport.

-iĝ- means become or get into a state.

Here, the passport became no longer valid. That is why -iĝ- is used: it describes a change of state.

If you used -ig- instead, that would mean cause something else to become that way. So eksvalidiĝinta is about the passport’s own state, not about someone actively causing it in this sentence.

-int- is the past active participle. It shows that the action happened before the main verb.

So the passport has already expired, and now it hinders the trip.

Compare:

• eksvalidiĝanta = expiring / in the process of expiring
• eksvalidiĝinta = expired / having expired
• eksvalidiĝonta = about to expire

Because pasporto is the subject of the sentence. It is the thing doing the action of malhelpas.

In Esperanto, the direct object usually takes -n, not the subject.

Because vojaĝon is the direct object.

The passport hinders the trip, so vojaĝon gets the accusative ending -n.

It comes from:

• helpi = to help
• mal- = the opposite

So malhelpi literally means something like to un-help, but in normal English it means to hinder, hamper, obstruct, get in the way of, and sometimes prevent.

In this sentence, it means the expired passport creates an obstacle for the trip.

La means the.

So la vojaĝon refers to a specific trip/journey, not just travel in general. Esperanto has no separate word for English a/an, so the presence or absence of la is important.

With la, the sentence suggests that the speaker has a particular trip in mind.

You could say malvalida pasporto, and it would mean an invalid passport.

But malvalida is broader: it only says the passport is not valid.

Eksvalidiĝinta is more specific. It says the passport used to be valid but has expired. So if the problem is expiration, eksvalidiĝinta is the better word.

No. Esperanto word order is fairly flexible because the object is marked by -n.

The neutral order is:

Eksvalidiĝinta pasporto malhelpas la vojaĝon.

But for emphasis, you could also say:

La vojaĝon malhelpas eksvalidiĝinta pasporto.

That still means basically the same thing, but the focus shifts a little.

Usually vojaĝo is most naturally trip or journey: a particular instance of traveling.

English travel can also work in some contexts, but it is often more general. In this sentence, the trip or the journey is probably the clearest translation.