Barnen leker i sanden på lekplatsen.

Because barnen is the definite plural form of barn.

• ett barn = a child
• barn = children / child in some contexts
• barnen = the children

A useful thing to know is that barn is one of those Swedish nouns whose indefinite singular and indefinite plural look the same:

• ett barn = a child
• två barn = two children
• barnen = the children

So in this sentence, barnen means we are talking about a specific group of children.

In Swedish, the definite article is often attached to the end of the noun instead of being a separate word.

So instead of saying:

• the children
• the sand
• the playground

Swedish says:

• barnen
• sanden
• lekplatsen

This is very normal in Swedish. The ending acts like the in English.

Leka is the infinitive form, meaning to play.
Leker is the present tense, meaning play / are playing.

So:

• leka = to play
• leker = play / are playing

In Swedish, the present tense often covers both English meanings:

• Barnen leker = The children play or The children are playing

The exact meaning depends on context.

It can mean both.

Swedish usually does not make the same strong distinction that English does between:

• they play
• they are playing

So Barnen leker can mean:

• The children play
• The children are playing

In this sentence, most learners would naturally understand it as are playing, because it sounds like a description of what is happening right now.

This is about Swedish prepositions, and they do not always match English exactly.

• i sanden = in the sand
• på lekplatsen = at/on the playground

i

I is used for being inside something or within an area/substance.

So i sanden suggests the children are physically in the sand, playing in it.

på

På is often used for locations such as:

• på lekplatsen = at the playground
• på skolan = at school
• på jobbet = at work

Even though på literally often means on, in many place expressions it is best learned as the natural Swedish choice rather than translated word-for-word.

Sanden means the sand, while sand means sand in a more general sense.

In this sentence, i sanden refers to the specific sand at the playground, so the definite form sounds natural.

Compare:

• Barnen leker i sanden. = The children are playing in the sand.
• Sand är gult. = Sand is yellow. / Sand is yellowish.

So here Swedish uses the definite form because it is talking about a specific, identifiable sand area.

Because lekplatsen is the definite singular form of lekplats.

• en lekplats = a playground
• lekplatsen = the playground

So the sentence is talking about a specific playground, not just any playground.

Also, lekplats is a common noun with en gender:

• en lekplats
• lekplatsen

Lekplats is a compound noun.

It is made up of:

• lek = play
• plats = place

So lekplats literally means play-place, which is the Swedish word for playground.

Compound nouns are very common in Swedish, and they are usually written as one word.

Yes, in a way. It is unusual because the indefinite singular and plural are the same:

• ett barn = a child
• flera barn = several children

Then the definite plural becomes:

• barnen = the children

So it is not completely irregular, but it does not follow the most predictable beginner pattern like:

• en bil → bilar → bilarna

That is why learners often notice barn early.

Yes, but Swedish has an important rule: the finite verb is usually in the second position in main clauses.

The original sentence is:

• Barnen leker i sanden på lekplatsen.

You can also move a place phrase to the front:

• På lekplatsen leker barnen i sanden.
• I sanden leker barnen på lekplatsen.

Notice that when another element comes first, leker still stays in the second position, and barnen moves after the verb.

This is called the V2 rule, and it is very important in Swedish.

A rough guide is:

Barnen leker i sanden på lekplatsen

Approximate pronunciation: BAR-nen LAY-ker ee SAN-den paw LEK-plat-sen

A few helpful notes:

• barnen: the a is broad, something like bah in many accents
• leker: le- sounds roughly like lay
• i is pronounced like English ee
• på has a long vowel, roughly paw or po
• lekplatsen is stressed mainly on the first part: LEK-

Pronunciation varies by region, but this approximation is good enough for a beginner.