Vindretningen endrer seg.

Because Norwegian, like German, very often forms compound nouns by writing the parts together as a single word.

Here:

• vind = wind
• retning = direction

So vindretning = wind direction.

Then Norwegian adds the definite ending to the whole compound:

• vindretning = wind direction
• vindretningen = the wind direction

This is very normal in Norwegian.

The ending -en marks the noun as definite singular for many masculine nouns.

With retning, the pattern is:

• en retning = a direction
• retningen = the direction

Since vindretning is a compound built on retning, it follows the same pattern:

• en vindretning = a wind direction
• vindretningen = the wind direction

So instead of putting the before the noun, Norwegian usually adds definiteness at the end.

Because the verb here is being used reflexively.

• å endre = to change something, to alter something
• å endre seg = to change, to change itself

In this sentence, the wind direction is not changing something else; it is itself changing. That is why Norwegian uses seg.

Compare:

• Han endrer planen. = He changes the plan.
• Planen endrer seg. = The plan changes.

So seg is important here.

Seg is a reflexive pronoun. It is used when the subject and the object refer to the same thing.

In English, this can sometimes correspond to:

• himself
• herself
• itself
• themselves

But Norwegian often uses seg in places where English would not use itself explicitly.

So although a very literal translation might look like The wind direction changes itself, the natural English meaning is just The wind direction changes.

Endrer is present tense.

The infinitive is:

• å endre = to change

The present tense is formed very simply:

• endrer = changes / is changing

In Norwegian, the present tense often covers both:

• changes
• is changing

So Vindretningen endrer seg can mean either, depending on context.

Because Norwegian usually uses the simple present where English may use either:

• changes
• is changing

So:

• endrer seg can mean changes or is changing

If you want to emphasize an ongoing action in Norwegian, there are ways to do it, but in ordinary sentences the simple present is very common and natural.

Yes. This is the basic Norwegian word order for a simple statement:

• Subject + verb + other elements

So:

• Vindretningen = subject
• endrer = verb
• seg = reflexive pronoun

That gives:

• Vindretningen endrer seg.

This is completely standard for a main clause.

The indefinite version would be:

• En vindretning endrer seg.

But in many contexts this sounds less natural, because people often mean a specific wind direction, or talk about the wind direction in general as a known thing:

• Vindretningen endrer seg. = The wind direction is changing.

So the definite form is very natural here.

A rough guide is:

• vind-ret-ning-en

A few useful points:

• vind ends with a clear d
• stress normally falls early in the word, roughly on vind
• retning has a short e
• the final -en is the definite ending

If you are learning pronunciation, it helps to hear native audio, because Norwegian pitch accent and vowel quality matter a lot more than English speakers often expect.

Yes, in many dialects and in Nynorsk or dialect-influenced speech, you may hear -a as the definite ending for some feminine nouns:

• vindretninga

In Bokmål, vindretningen is the standard written form most learners will meet first.

So:

• vindretningen = standard Bokmål form
• vindretninga = common in some varieties and dialectal usage

Both are understandable, but vindretningen is the safest form for learners to use first.