Passintarkastuksen jälkeen menemme portille, jossa muut matkustajat jo odottavat.

Because jälkeen is a postposition meaning after, and postpositions usually require the noun before them to be in a specific case. Here, jälkeen takes the genitive.

So:

• passintarkastus = passport control / passport check
• passintarkastuksen = genitive form of that noun
• passintarkastuksen jälkeen = after passport control

This is a very common pattern in Finnish:

• ruoan jälkeen = after the food / after eating
• koulun jälkeen = after school

It works like an English preposition in meaning, but structurally it is a postposition, which means it comes after the noun instead of before it.

Compare:

• English: after passport control
• Finnish: passintarkastuksen jälkeen = literally passport control's after

Finnish has both prepositions and postpositions, but postpositions are very common.

Because the verb ending already tells you the subject.

• menemme = we go / we are going

The ending -mme marks first person plural (we), so me is not necessary.

You could say Me menemme, but it is usually only used for emphasis or contrast:

• Me menemme portille, he jäävät tänne. = We are going to the gate, they are staying here.

It is the 1st person plural present tense of mennä (to go).

Breakdown:

• dictionary form: mennä
• stem used here: mene-
• ending for we: -mme
• menemme = we go / we are going

In Finnish, the present tense can often translate as either simple present or present continuous in English, depending on context.

Portille is the allative form of portti, and it means to the gate / onto the gate area / up to the gate.

• portti = gate
• portille = to the gate

Finnish uses different location cases depending on how a place is understood. With airport gates, -lle is natural because you are going to that point/location.

Very roughly:

• portille = to the gate
• portilla = at the gate
• portilta = from the gate

A learner may expect porttiin, but that would sound more like going into a physical gate or opening. In airport language, portille is the normal choice.

Jossa means where or more literally in/at which.

It introduces a relative clause that describes portille:

• portille, jossa muut matkustajat jo odottavat
• to the gate, where the other passengers are already waiting

It comes from the relative pronoun joka plus the inessive ending -ssa:

• joka = who / which / that
• jossa = in which / where

Because the case of jossa is chosen by its role in the relative clause, not by the case of portille in the main clause.

Main clause:

• menemme portille = we go to the gate

Relative clause:

• jossa muut matkustajat jo odottavat = where the other passengers are already waiting

So the gate has two different roles:

• in the main clause, it is a destination → portille
• in the relative clause, it is a location → jossa

This is very normal in Finnish.

It means the other passengers.

• muut = other, others
• matkustajat = passengers

Together, muut matkustajat means the passengers other than us or other than the ones already implied by context.

Finnish often leaves out articles, so muut matkustajat can mean:

• other passengers
• the other passengers

The exact English version depends on context.

Because the subject is plural.

• matkustaja = passenger
• matkustajat = passengers

Finnish verbs agree with the subject in number and person:

• matkustaja odottaa = the passenger is waiting
• matkustajat odottavat = the passengers are waiting

So muut matkustajat jo odottavat is a normal plural subject + plural verb combination.

Jo means already.

So:

• muut matkustajat jo odottavat = the other passengers are already waiting

It often appears before the verb, as it does here. Its placement is quite natural and idiomatic.

Compare:

• Hän on jo täällä. = He/She is already here.
• Me menemme jo. = We are leaving already / We’re going now already.

Because Finnish has no articles.

There is no direct equivalent of English a/an or the in ordinary Finnish grammar. Definiteness is understood from context.

So:

• portille can mean to a gate or to the gate
• muut matkustajat can mean other passengers or the other passengers

When translating into English, you choose the article that sounds natural in context.

Yes. Finnish forms compound nouns very freely, much more than English does.

• passi = passport
• tarkastus = inspection, check
• passintarkastus = passport inspection / passport control

Notice that the first part often changes form slightly inside a compound. Here passi becomes passin- before tarkastus.

Compound nouns are extremely common in Finnish, so getting comfortable with them is important.

Yes, Finnish word order is fairly flexible, although this sentence is the most neutral and natural version.

The given order is good because it flows clearly:

1. time expression: Passintarkastuksen jälkeen
2. main action: menemme portille
3. extra information about the gate: jossa muut matkustajat jo odottavat

You may see other orders for emphasis, but they can change the focus. For a learner, the original sentence is a very good standard model.

Yes, very roughly:

• Passintarkastuksen jälkeen = after passport control
• menemme = we go
• portille = to the gate
• jossa = where / at which
• muut matkustajat = the other passengers
• jo = already
• odottavat = are waiting / wait

A very literal version would be:

After passport control we go to the gate where the other passengers already wait.

That is not the most natural English, but it helps show how the Finnish sentence is built.