Barnen får inte köra kundvagnen för fort i butiken.

Because barn is the noun child / children, and -en here marks the definite plural.

• ett barn = a child
• barnet = the child
• barn = children
• barnen = the children

So Barnen at the start of the sentence means the children.

A useful thing to notice is that barn has the same form in singular indefinite and plural indefinite:

• ett barn = a child
• barn = children

That can feel unusual to English speakers at first.

Here får inte means are not allowed to or must not.

• får is the present tense of få
• få can mean several things, including get, receive, or be allowed to
• in this sentence, it has the permission meaning

So:

• Barnen får köra kundvagnen = The children are allowed to push/drive the shopping cart
• Barnen får inte köra kundvagnen = The children are not allowed to push/drive the shopping cart

This is a very common Swedish pattern:

• Jag får gå nu. = I’m allowed to go now.
• Du får inte röka här. = You must not smoke here.

Because in a normal Swedish main clause, the finite verb usually comes in second position, and inte normally comes after that verb.

So the order is:

• Barnen (subject)
• får (finite verb)
• inte (negation)
• köra (infinitive)

This is standard Swedish word order.

Compare:

• Barnen får inte köra kundvagnen.
• Jag kan inte komma.
• Hon vill inte äta.

English often places not differently, so this is something learners need to get used to.

Because after modal-like verbs such as får, Swedish uses the infinitive without att.

So:

• får köra = may / are allowed to drive
• kan köra = can drive
• vill köra = want to drive
• måste köra = must drive

Not:

• får att köra ❌

This is similar to English, where we say:

• can drive
• must drive

not can to drive.

Literally, köra often means drive. But in Swedish it is also used more broadly for operating, moving, or pushing something in a controlled way.

So with kundvagnen, köra is very natural and means something like:

• push the shopping cart
• steer the shopping cart
• drive the shopping cart (more literal)

English usually says push a shopping cart, but Swedish commonly says köra kundvagnen.

Kundvagnen means the shopping cart.

It is a compound noun:

• kund = customer
• vagn = wagon / cart

So:

• kundvagn = shopping cart
• kundvagnen = the shopping cart

Swedish forms compounds very freely, much more than English does. Where English often uses two words, Swedish often uses one:

• kundvagn = shopping cart
• sjukhus = hospital
• fotbollsmatch = football match

This is extremely common in Swedish.

Because the base word is kundvagn, not kundvagn with a different ending pattern.

Break it down:

• kund
  • vagn = kundvagn
• definite singular of kundvagn = kundvagnen

The definite ending -en is added to the whole compound noun.

So:

• en kundvagn = a shopping cart
• kundvagnen = the shopping cart

Because the sentence is talking about the shopping cart as the thing the children are using.

In context, this often means:

• a specific cart
• the cart they have
• the store cart in the situation being discussed

Swedish often uses the singular when one shared object is meant.

If you wanted to talk about shopping carts in general, you might say something like:

• Barnen får inte köra kundvagnar för fort i butiken. = The children must not push shopping carts too fast in the store.

But the original sentence sounds like it is about the cart in that situation.

För fort means too fast.

Here för does not mean English for.
Instead, för is an adverb meaning too when it comes before an adjective or adverb.

So:

• fort = fast / quickly
• för fort = too fast / too quickly

More examples:

• för dyr = too expensive
• för långsamt = too slowly
• för sent = too late

This is a very important use of för in Swedish.

Here fort is functioning as an adverb, meaning quickly / fast.

In the sentence, it describes how they drive/push the shopping cart:

• köra ... fort = drive/push ... fast

Swedish often uses fort where English uses fast or quickly.

Examples:

• Han springer fort. = He runs fast.
• Kör inte så fort! = Don’t drive so fast!

Because i means in, and butiken means the store / the shop.

So:

• i butiken = in the store

This is natural because the children are physically inside the store.

Forms:

• en butik = a store
• butiken = the store

So the ending -en again marks the definite form.

Yes, often you could.

• butik = shop/store
• affär = shop/store/business

So:

• i butiken
• i affären

can both mean in the store/shop, depending on context.

In everyday Swedish, both are common, though butik may sound a bit more directly like a retail store.

The sentence follows a very typical Swedish main-clause pattern:

• Barnen = subject
• får = finite verb
• inte = negation
• köra = infinitive
• kundvagnen = object
• för fort = adverbial phrase
• i butiken = place

So the structure is:

Subject + finite verb + inte + infinitive + object + adverb + place

That makes this sentence a very good example of standard Swedish word order.

Yes. Depending on context, får inte can range from:

• are not allowed to
• must not
• can’t
• don’t get to

In this sentence, the most natural meaning is a rule or prohibition:

• The children must not / are not allowed to push the shopping cart too fast in the store.

So it is not mainly about ability; it is about permission.

Because Swedish does not need do-support the way English does.

English says:

• The children do not drive...
• The children are not allowed to...

Swedish usually just puts inte after the finite verb:

• Barnen kör inte...
• Barnen får inte köra...

There is no extra helper like English do.

This is one of the major structural differences between English and Swedish.

Yes, it is completely natural.

It sounds like something you might see or hear in a store, especially as a rule or warning:

• children must not push the shopping cart too fast in the store

It is straightforward, idiomatic Swedish, and it uses very common grammar:

• definite plural subject
• får inte for prohibition
• infinitive without att
• compound noun
• för meaning too

So it is a very useful sentence to study.