Passintarkastus sujui nopeasti, koska kaikki paperit olivat valmiina.

Passintarkastus is a compound noun:

• passin = of the passport / passport's
  
  • from passi = passport
  • passin is the genitive singular
• tarkastus = inspection, check

So passintarkastus literally means passport inspection/check, which in natural English is often passport control or passport check.

This kind of compound is very common in Finnish.

Sujui is the past tense of sujua.

• sujua = to go well, to proceed, to run smoothly
• sujui = went, proceeded, went smoothly

In this sentence, Passintarkastus sujui nopeasti means something like:

• The passport check went quickly
• Passport control went smoothly and quickly

A useful thing to notice is that Finnish often uses verbs like sujua where English might use go, proceed, or run.

Example:

• Kokous sujui hyvin. = The meeting went well.

Because nopeasti is an adverb, while nopea is an adjective.

• nopea = fast, quick
• nopeasti = quickly, fast

Here the word describes how the passport check went, so Finnish uses the adverb:

• sujui nopeasti = went quickly

A very common way to form adverbs in Finnish is:

• adjective stem + -sti

For example:

• hidas → hitaasti = slowly
• varma → varmasti = certainly / surely
• nopea → nopeasti = quickly

In this sentence, kaikki paperit means all the papers or all the documents.

• kaikki = all
• paperit = papers, documents

In context, paperit often means documents, not just physical sheets of paper. So this could mean passports, forms, visas, tickets, or other travel documents.

Because Finnish has no articles like a or the, kaikki paperit can be translated depending on context as:

• all papers
• all the papers
• all the documents

Here, all the documents is often the most natural English meaning.

Because paperit here is the plural nominative, which is used for a complete, definite set.

• paperit = the papers / the documents as a whole set
• papereita = (some) papers / documents, often indefinite or partitive

So:

• kaikki paperit olivat valmiina = all the papers were ready
  • the full set was ready
• papereita oli pöydällä = there were papers on the table
  • just some papers, not necessarily a complete known set

With kaikki, Finnish often uses the nominative when talking about the full set:

• kaikki ihmiset
• kaikki kirjat
• kaikki paperit

Both are in the Finnish past tense (often called the imperfect).

• sujui = went / proceeded
• olivat = were

So the sentence describes a past situation:

• Passintarkastus sujui nopeasti = The passport check went quickly
• kaikki paperit olivat valmiina = all the papers were ready

This is a very normal way to talk about a completed event in the past.

Because the subject is plural:

• kaikki paperit = all the papers → plural

So the verb olla must also be plural in the past tense:

• oli = was (singular)
• olivat = were (plural)

Compare:

• Paperi oli valmiina. = The paper was ready.
• Paperit olivat valmiina. = The papers were ready.

This is one of the most useful questions in the sentence.

Valmiina is the essive case of valmis.

• valmis = ready, finished
• valmiina = in a ready state, ready/available/on hand

The expression olla valmiina is very common and means:

• to be ready
• to be prepared
• to be available and ready for use

So:

• paperit olivat valmiina = the papers were ready / already prepared / at hand

Why not valmiit?

• valmiit is the plural nominative form of the adjective.
• paperit olivat valmiit can sound more like the papers were completed/finished
• paperit olivat valmiina emphasizes that they were ready and available for use when needed

In this context, valmiina is the natural choice.

A few similar examples:

• Ruoka on valmiina. = The food is ready.
• Olen valmiina. = I am ready.
• Kaikki on valmiina. = Everything is ready.

The essive case often expresses a state, role, or condition.

Its ending is usually:

• -na / -nä

In valmiina, it shows the state of being ready.

So olla valmiina is literally something like:

• to be in a ready state

This case is also used in other common expressions:

• lapsena = as a child
• opettajana = as a teacher
• yksinään is related historically, though used a bit differently
• suljettuna = closed
• auki / avoinna = open

For learners, the most important thing is simply to recognize olla valmiina as a fixed, common structure meaning to be ready.

Koska means because in this sentence.

• Passintarkastus sujui nopeasti, koska kaikki paperit olivat valmiina.
• The passport check went quickly because all the papers were ready.

It introduces a subordinate clause that gives the reason.

Be careful: koska can also mean when in some contexts.

Examples:

• En tullut, koska olin sairas. = I didn't come because I was sick.
• Koska lähdet? = When are you leaving?

So the meaning depends on context. In your sentence, it clearly means because.

Because Finnish normally uses a comma to separate a main clause from a subordinate clause.

Here:

• Main clause: Passintarkastus sujui nopeasti
• Subordinate clause: koska kaikki paperit olivat valmiina

So the comma is standard Finnish punctuation.

This often feels a bit more systematic than in English, where comma use can be less regular.

Yes. Finnish allows that very naturally:

• Koska kaikki paperit olivat valmiina, passintarkastus sujui nopeasti.

This means the same thing:

• Because all the papers were ready, the passport check went quickly.

The difference is mostly about emphasis:

• Passintarkastus sujui nopeasti... starts with the result
• Koska kaikki paperit olivat valmiina... starts with the reason

Both are correct.

Because Finnish does not have articles like a, an, or the.

So Finnish often leaves that idea to be understood from context.

For example:

• passintarkastus can mean passport control, the passport check, or a passport check
• paperit can mean papers, the papers, or documents

In this sentence, English naturally uses the:

• The passport check went quickly because all the papers were ready.

But Finnish does not need a separate word for that.

It can definitely mean documents, and that is probably the most natural meaning here.

In travel or official situations, paperit often means things like:

• passport
• ID
• visa
• tickets
• forms
• supporting documents

So in this sentence, a natural understanding is:

• all the documents were ready

Even though the literal word is papers, Finnish uses it broadly, much like English sometimes does in expressions like Do you have your papers?

There are other possibilities, depending on context.

For example:

• passintarkastus = passport check / passport control
• rajatarkastus = border check / border control
• passikontrolli may sometimes be heard in more informal or borrowed-style usage, but passintarkastus is the standard Finnish-style compound

So passintarkastus is a very natural and correct word here.

The word order is:

• Passintarkastus = subject/topic
• sujui = verb
• nopeasti = adverb
• koska kaikki paperit olivat valmiina = reason clause

So the structure is roughly:

• [subject] + [verb] + [adverb] + [because-clause]

Finnish word order is fairly flexible, but this is a very normal, natural sentence.

Because Finnish uses cases and verb forms to show grammatical relationships, it can move elements around more freely than English. Still, the version given is neutral and idiomatic.

A few very useful takeaways:

• Compound nouns are common
  
  • passintarkastus
• sujua is a common verb for events that go or proceed
  • sujui nopeasti
• nopeasti is an adverb
  • adjective nopea → adverb nopeasti
• paperit often means documents
• olla valmiina is a very common expression
  • to be ready
• koska can mean because
• Finnish uses no articles
  • no separate word for the

If you remember just one chunk from this sentence, olla valmiina is especially worth learning as a set expression.