Kaupungissa asuu miljoona ihmistä.

Kaupungissa is the form of kaupunki meaning in the city.

The ending -ssa is the inessive case, which often corresponds to English in.

• kaupunki = city
• kaupungissa = in the city / in a city

Finnish often uses case endings where English uses prepositions.

Because the word stem changes before many endings.

With kaupunki, the stem used in forms like the genitive and inessive is kaupungi-:

• kaupunki = city
• kaupungin = of the city
• kaupungissa = in the city

This is part of a common Finnish pattern involving stem changes and consonant gradation. For a learner, it is often easiest to memorize the basic set together:

• kaupunki
• kaupungin
• kaupungissa

Grammatically, the key word here is miljoona, which is singular.

So Finnish treats the phrase as a singular quantity expression:

• miljoona ihmistä = a million people

Because miljoona is singular, the verb is also singular:

• asuu = lives / is living

If the subject were something like ihmiset (the people), then the verb would be plural:

• Ihmiset asuvat kaupungissa. = The people live in the city.

After numbers greater than one, Finnish normally uses the counted noun in the partitive singular.

So:

• yksi ihminen = one person
• kaksi ihmistä = two people
• miljoona ihmistä = a million people

That is why ihmistä appears here. Even though the meaning is plural in English, Finnish uses this number pattern.

The dictionary form is ihminen = person / human.

This word changes quite a lot in different forms:

• ihminen = person
• ihmisen = of the person
• ihmistä = person/people in the partitive

Words ending in -nen often change their stem in other forms, so ihminen becomes ihmis- in many inflected forms.

Finnish word order is more flexible than English word order.

Starting with Kaupungissa puts the location first and sets the scene: In the city... This is very natural in Finnish, especially when introducing what exists or lives somewhere.

So this sentence feels a bit like:

• In the city, there live a million people
• more naturally in English: A million people live in the city

You can also say:

• Miljoona ihmistä asuu kaupungissa.

That is also correct, but it sounds more like a regular statement about a million people, while Kaupungissa asuu... emphasizes the location first.

Yes. It is a very typical existential sentence.

An existential sentence often has this pattern:

• [place] + [verb] + [thing/person]

It is used to say that something exists, is located, or lives somewhere.

Examples:

• Pihalla on koira. = There is a dog in the yard.
• Huoneessa on pöytä. = There is a table in the room.
• Kaupungissa asuu miljoona ihmistä. = A million people live in the city.

This helps explain why the place word comes first and why the structure may feel different from English.

Because Finnish has no articles like a, an, or the.

So kaupungissa by itself can mean:

• in the city
• in a city

The exact meaning depends on context. In many translations, English uses the city because that sounds most natural in context, but Finnish does not need a separate word for that.

Yes, that is a very natural English way to express the same idea.

Because the Finnish structure is existential-like, English often has more than one good translation:

• A million people live in the city.
• There are a million people living in the city.

Both capture the idea well, even though the Finnish sentence literally starts with the location: In the city...