Meillä on välilasku Tukholmassa, joten en nuku kovin hyvin koneessa.

Finnish often expresses possession with the pattern:

owner + adessive case + on

So:

• meillä = at us / with us
• on = is

Literally, Meillä on välilasku is something like At us there is a stopover, but in natural English that means We have a stopover.

This is a very common Finnish structure:

• Minulla on auto = I have a car
• Meillä on kiire = We are in a hurry / We have a hurry

Meillä is the adessive form of me = we.

The adessive ending is usually -lla / -llä, and one of its main uses is to show:

• possession: meillä on = we have
• location: pöydällä = on the table
• association: minulla = with me / I have

So here meillä does not mean we as the subject in the usual English sense. It means something more like with us or for us.

Välilasku means stopover, layover, or intermediate landing during a flight.

It is a compound word:

• väli = interval / in-between
• lasku = descent / landing

So the idea is an in-between landing.

A useful nuance:

• välilasku focuses on the stop/landing itself
• if you want to emphasize changing planes, Finnish may use words like vaihto or koneenvaihto

Because Finnish marks location with case endings instead of separate prepositions like in.

• Tukholma = Stockholm
• Tukholmassa = in Stockholm

The ending -ssa / -ssä is the inessive case, often translated as in.

So:

• välilasku Tukholmassa = a stopover in Stockholm

This is very normal with city names:

• Helsingissä = in Helsinki
• Lontoossa = in London
• Tukholmassa = in Stockholm

This is because of vowel harmony.

Finnish case endings often have two versions:

• -ssa after back vowels (a, o, u)
• -ssä after front vowels (ä, ö, y)

Since Tukholma contains back vowels, the ending is -ssa:

• Tukholma → Tukholmassa

Compare:

• kylä → kylässä
• metsä → metsässä

The letters e and i are neutral and can go with either type.

Joten means so, therefore, or which is why.

It introduces a result or consequence:

• Meillä on välilasku Tukholmassa, joten en nuku kovin hyvin koneessa.
• We have a stopover in Stockholm, so I don’t sleep very well on the plane.

It is different from koska:

• joten = so / therefore
• koska = because

So you could also say:

• En nuku kovin hyvin koneessa, koska meillä on välilasku Tukholmassa.

That means the same basic thing, but the logic is expressed from the other direction.

Finnish forms negation with a special negative verb.

In the present tense, the negative verb changes for person:

• en = I do not
• et = you do not
• ei = he/she/it does not
• emme = we do not
• ette = you plural do not
• eivät = they do not

Then the main verb appears in a special form:

• nukun = I sleep
• en nuku = I do not sleep

So in this sentence:

• en = I do not
• nuku = sleep

This is completely standard Finnish grammar.

Because Finnish often leaves subject pronouns out when they are already clear from the verb form.

• en already tells you the subject is I
• so minä is not necessary

That is why:

• en nuku = I don’t sleep

If you add minä, it usually gives extra emphasis or contrast:

• joten minä en nuku kovin hyvin koneessa
• so I’m the one who doesn’t sleep very well on the plane

Without minä, the sentence sounds more neutral and natural.

• hyvin = well
• kovin in negative sentences often means very, particularly, or all that

So:

• en nuku hyvin = I don’t sleep well
• en nuku kovin hyvin = I don’t sleep very well

This makes the statement a bit softer and more natural.

A very important point: kovin is especially common with negation.

So learners will often hear:

• ei kovin hyvä = not very good
• en kovin usein = not very often
• en nuku kovin hyvin = I don’t sleep very well

Yes, kone can mean machine, but in travel contexts it often means plane.

So:

• koneessa = in the plane / on the plane

Finnish often uses kone as shorthand for lentokone = airplane.

Also, Finnish usually uses the inessive case for being inside vehicles:

• autossa = in the car
• junassa = on the train / in the train
• bussissa = on the bus / in the bus
• koneessa = on the plane / in the plane

English prefers on the plane, but Finnish uses a form that is literally more like in the plane.

Because Finnish has no articles.

There is no direct equivalent of English a/an/the. Whether something is:

• a stopover
• the stopover
• a plane
• the plane

is understood from context.

So:

• välilasku can mean a stopover or the stopover
• koneessa can mean on the plane or on a plane

The listener figures it out from the situation.

The word order in this sentence is quite natural and neutral, but Finnish word order is more flexible than English.

This version presents:

1. the situation: Meillä on välilasku Tukholmassa
2. the consequence: joten en nuku kovin hyvin koneessa

You can often move things around for emphasis, for example:

• Koneessa en nuku kovin hyvin, koska meillä on välilasku Tukholmassa.
• En nuku kovin hyvin koneessa, koska meillä on välilasku Tukholmassa.

But the original sentence is a very normal, straightforward way to say it.

Yes.

• koneessa = on the plane
• lentokoneessa = on the airplane

Lentokoneessa is more explicit, while koneessa is shorter and very natural when the context is clearly about flying.

So both are possible, but koneessa sounds more everyday here.