Learn Hardcore Norwegian: Det er billigere å kjøpe grønnsaker på markedet enn i butikken. - It is cheaper to buy vegetables at the market than in the store.

In Det er billigere å kjøpe grønnsaker på markedet enn i butikken, the det is a dummy subject, just like it in English It is cheaper to buy vegetables at the market than in the shop.

It doesn’t refer to any concrete thing.
This det er pattern is very common in Norwegian when making general statements or introducing something:
- Det er kaldt i dag. – It’s cold today.
- Det er vanskelig å lære norsk. – It’s hard to learn Norwegian.

So det here is only grammatical: you can’t replace it with a specific noun.

Why is it billigere and not mer billig for cheaper?

Norwegian usually forms the comparative of most short, common adjectives by adding -ere:

billig → billigere (cheap → cheaper)
dyr → dyrere (expensive → more expensive)
stor → større (big → bigger)

Using mer billig is technically understandable but sounds unnatural and non‑native. For billig, the normal comparative is billigere.

A few adjectives do use mer instead of -ere, especially longer or loaned adjectives:

interessant → mer interessant (interesting → more interesting)

But billig is not one of them; it takes -ere.

What is the role of å in å kjøpe? Why do we need it?

Å is the infinitive marker in Norwegian, like to in English before a verb:

å kjøpe – to buy
å spise – to eat
å lære – to learn

In this sentence, å kjøpe grønnsaker på markedet is an infinitive phrase functioning like a noun phrase:

Det er billigere [å kjøpe grønnsaker på markedet] …
→ It is cheaper [to buy vegetables at the market] …

So you need å in front of kjøpe because you’re using the infinitive, not a finite verb form.

Why is it kjøpe and not kjøper?

Kjøpe is the infinitive form, used after å:

å kjøpe – to buy
jeg kjøper – I buy / I am buying

After å, you must use the infinitive:

å spise, not å spiser
å snakke, not å snakker
å kjøpe, not å kjøper

So kjøpe is correct here because the verb depends on å.

Why is grønnsaker plural? Could you say grønnsak instead?

Grønnsaker is the plural of grønnsak (vegetable → vegetables).

In English, you can often say to buy vegetables or to buy vegetable(s), but in Norwegian, when you speak generally about this kind of food, you typically use the plural:

Jeg liker grønnsaker. – I like vegetables.
Han spiser mye grønnsaker. – He eats a lot of vegetables.

Grønnsak (singular) would refer to one vegetable:

Jeg kjøpte én grønnsak. – I bought one vegetable.

So grønnsaker is the natural choice in a general statement about buying vegetables.

Why is it på markedet and not i markedet?

The preposition på is used here because markedet is understood as an open market / marketplace, more like an area/event than the inside of a building.

In Norwegian:

på markedet – at the market (as a place / event)
i markedet – in the market (more abstract, like in the market for used cars, or literally inside a (very rare) closed “market” space)

For physical places, på is common when you think of a place as a surface, area, or event:

på skolen – at (the) school
på kino – at the cinema
på jobb – at work

So på markedet is the idiomatic way to say at the market.

Why is it markedet (with -et) and not just marked?

Markedet is the definite singular form: the market.

et marked – a market
markedet – the market

Norwegian uses the definite form a lot, often more than English. English has the market here, and Norwegian matches that.

You could say på et marked (at a market) if you meant some market or other, but in a general comparison like this, på markedet feels more natural to native speakers: they imagine a specific local market people know about (e.g. the town market).

Why is it i butikken and not på butikken?

The common and neutral expression is i butikken – literally in the shop / in the store, but it also covers the English meaning at the shop.

i butikken – in/at the shop
på butikken – used regionally (especially in some dialects); many speakers will still understand it, but in standard Bokmål i butikken is preferred.

Norwegian often uses i for being inside or at many types of buildings:

i huset – in the house
i banken – at the bank
i kirken – in/at the church

So for standard written Norwegian, i butikken is the best choice.

Why is butikken definite (with -en) instead of just butikk?

Butikken is the shop, definite singular:

en butikk – a shop
butikken – the shop

Norwegian tends to use the definite form when English uses the or even when English doesn’t use any article, especially in set places people normally go to:

på skolen – at school
i kirken – at church
i butikken – at the shop

Here you’re comparing two specific types of places that are familiar concepts: the market vs the shop, so the definite forms markedet and butikken feel natural.

What does enn mean, and how do you use it?

Enn corresponds to English than in comparisons.

Pattern:

A er adjektiv‑ere enn B
– A is more adjective than B.

Examples:

Han er høyere enn broren sin. – He is taller than his brother.
Det er dyrere å bo i Oslo enn i Tromsø. – It is more expensive to live in Oslo than in Tromsø.

In your sentence:

Det er billigere å kjøpe grønnsaker på markedet enn i butikken.
– It is cheaper to buy vegetables at the market than in the shop.

Note that after enn, some words can be left out if they are understood from context (see next question).

Why is it just enn i butikken and not enn å kjøpe dem i butikken?

Norwegian allows ellipsis in comparisons: you can leave out repeated words that are clearly understood.

Full, explicit version:

Det er billigere å kjøpe grønnsaker på markedet enn å kjøpe dem i butikken.

In normal speech and writing, you drop the repeated part:

… enn i butikken.
→ You understand it as than (it is to buy them) in the shop.

This is similar to English:

It’s cheaper to buy vegetables at the market than (to buy them) in the shop.

Could we say Å kjøpe grønnsaker på markedet er billigere enn i butikken instead? Is that different?

Yes, that sentence is also correct:

Å kjøpe grønnsaker på markedet er billigere enn i butikken.

Difference in nuance:

Det er billigere å kjøpe …
– Uses dummy det; very common, feels a bit more neutral and natural in many contexts.
Å kjøpe … er billigere …
– Puts the action to buy vegetables at the market directly in subject position, giving it slightly more emphasis.

Meaning‑wise, they are essentially the same, and both are acceptable.

How do you pronounce kjøpe and grønnsaker? The kj and ø look tricky.

Approximate Bokmål pronunciation (standard Eastern accent):

kjøpe → [ˈçøːpə]
- kj → a voiceless palatal fricative [ç], somewhat like the h in German ich.
- ø → like the vowel in French peu or German schön; round your lips while saying something like e.
grønnsaker → [ˈgrønnˌsɑːkər] (or [ˈgrønˌsɑːkər], depending on speaker)
- ø again as above.
- Double nn indicates a short preceding vowel and a long consonant sound.
- a in saker is a long a, similar to the a in British father.

You don’t need to be perfect at kj and ø to be understood, but aiming for something between English sh and h for kj, and a rounded e for ø, will get you close.