Sittehøyden og bordhøyden justeres sammen.

They are compound nouns, which are very common in Norwegian.

• sittehøyden = sitte
  • høyden
• bordhøyden = bord
  • høyden

The last part, høyde, means height, and the first part tells you what kind of height it is:

• sittehøyde = sitting height / seat height
• bordhøyde = table height

In Norwegian, compounds are usually written as one word, not as separate words.

Because they are in the definite singular form.

The base noun is:

• en høyde = a height

Its definite form is:

• høyden = the height

Since the whole compound is treated like one noun, the definite ending goes on the last part:

• sittehøyde → sittehøyden
• bordhøyde → bordhøyden

So the ending -en is basically doing the job of English the.

In Norwegian, the definite article is often attached to the end of the noun instead of standing as a separate word.

So instead of saying something like the seat height, Norwegian commonly says:

• sittehøyden

not a separate the + noun structure.

This is normal Norwegian grammar, not something special about this sentence.

Justeres is the present tense s-passive form of justere.

• å justere = to adjust
• justerer = adjusts / adjust
• justeres = is adjusted / are adjusted

So justeres gives the sentence a passive meaning: the focus is on the heights being adjusted, not on who adjusts them.

This -s passive is especially common in:

• instructions
• product descriptions
• technical writing
• formal style

Because Norwegian can form the passive in two main ways:

1. s-passive
   • justeres
2. bli + past participle
   • blir justert

Both can mean is/are adjusted, but justeres is shorter and very common in written, technical, or neutral descriptions.

So:

• Sittehøyden og bordhøyden justeres sammen.

is a compact, natural way to say that the two heights are adjusted together.

Because Norwegian verbs do not change form for singular vs. plural subjects the way English verbs sometimes do.

In English, you compare:

• it is
• they are

But in Norwegian, the verb form usually stays the same regardless of number.

So whether the subject is one thing or several things, you still use the same present passive form:

• høyden justeres
• høydene justeres

This is very normal in Norwegian.

Sammen means together.

In this sentence, it suggests that the seat height and the table height are adjusted:

• at the same time
• in coordination
• as linked settings rather than separately

So sammen is important because it tells you the two things are treated as a pair.

This is standard Norwegian main-clause word order:

• subject
  • verb
    • other information

Here the subject is the whole phrase:

• Sittehøyden og bordhøyden

Then comes the verb:

• justeres

Then the adverb:

• sammen

So the structure is:

• [subject] [verb] [adverb]

Also, even though the subject contains two nouns joined by og, it still functions as one subject unit.

It is natural Norwegian, but it sounds especially typical of:

• manuals
• product descriptions
• catalog text
• technical explanations

In everyday speech, people might say something more conversational if they want to mention who does the adjusting, for example with du or another clearer context.

But as a neutral written statement, this sentence sounds completely normal.

In Norwegian compounds, the first part often gets the strongest stress.

So you would typically hear stress like this:

• SITTEhøyden
• BORDhøyden

That first element tells you what type of height is meant, so it naturally carries strong emphasis.

This is a useful general rule for Norwegian compound words.