Barnet ser vesenet.

Because -et is the common definite singular ending for many neuter nouns in Norwegian.

• et barn → barnet
• et vesen → vesenet

So both words end in -et because both nouns are neuter, and both are in the definite singular form.

Norwegian nouns have grammatical gender. These two nouns are neuter nouns, so they take et in the indefinite singular:

• et barn
• et vesen

Many common nouns take en, but not all. Gender has to be learned with the noun.

In Norwegian, the is often added as a suffix to the noun instead of appearing as a separate word.

So English:

• the child
• the being

becomes Norwegian:

• barnet
• vesenet

This is one of the biggest differences from English. Norwegian often puts the definiteness directly onto the noun.

The dictionary forms are:

• barn = child
• vesen = being / creature

When you want the indefinite singular, you usually say:

• et barn
• et vesen

When you want the definite singular, you get:

• barnet
• vesenet

Ser is the present tense of å se (to see).

Examples:

• jeg ser = I see
• du ser = you see
• barnet ser = the child sees

Norwegian verbs do not change according to the subject the way English verbs sometimes do. The same present-tense form ser is used with all persons.

In this sentence, ser most naturally means sees.

If you want to say looks at, Norwegian often uses ser på:

• Barnet ser på vesenet. = The child is looking at the being/creature.

So:

• ser = sees
• ser på = looks at

That is a very common thing for learners to mix up.

Because of the normal Norwegian word order: subject + verb + object.

Here:

• Barnet = subject
• ser = verb
• vesenet = object

So the sentence means that the child is doing the seeing.

If you switched the nouns, the meaning would change:

• Vesenet ser barnet. = The being sees the child.

It would be:

• Et barn ser et vesen.

That means a child sees a being/creature.

So the contrast is:

• Barnet ser vesenet. = definite
• Et barn ser et vesen. = indefinite

It exists in modern Norwegian, but it is not as everyday as many simpler nouns. It can sound a bit literary, formal, or story-like depending on context.

It can mean something like:

• being
• creature
• entity

So learners may see it in fiction, fantasy, folklore, or more formal writing.

Usually barn means child, but it can be used in a few related ways depending on context.

For example:

• a young person: et barn
• someone’s son or daughter: hun har tre barn = she has three children

So barnet most naturally means the child, not specifically the baby.

Yes, but then Norwegian usually uses double definiteness.

For example:

• det lille barnet ser det rare vesenet

Here you get:

• a separate definite word: det
• and the definite ending on the noun: -et

This is different from English and is another common feature learners notice.