Noteheftet krever god notekunnskap.

Because Norwegian usually marks definiteness by adding an ending to the noun.

• et hefte = a booklet / a workbook
• heftet = the booklet / the workbook

Here, notehefte is a compound noun:

• note
  • hefte = notehefte

Since hefte is a neuter noun, the definite singular form ends in -et:

• et notehefte = a music booklet / notation workbook
• noteheftet = the music booklet / the notation workbook

So noteheftet means the note booklet/workbook, not just a booklet.

In this sentence, note is most naturally understood as musical note rather than a written note for class.

So notehefte most likely means something like:

• music booklet
• booklet with musical notation
• music workbook
• possibly sheet-music booklet, depending on context

The exact English word depends on the situation, but the important point for a learner is that this is a compound noun built from two smaller words:

• note = note
• hefte = booklet / workbook / pamphlet

Krever is the present tense form of the verb å kreve.

• å kreve = to require
• krever = requires / require

Norwegian verbs do not change for person the way English verbs do. So the same present-tense form is used with all subjects:

• jeg krever
• du krever
• han/hun krever
• vi krever

In this sentence:

• Noteheftet krever ... = The booklet requires ...

They can both sometimes relate to necessity, but they are not used in exactly the same way.

• krever = requires / demands
• trenger = needs

In this sentence, krever is the natural choice because the subject is something like a book or exercise material, and the meaning is that it requires a certain level of skill.

So:

• Noteheftet krever god notekunnskap = The booklet requires good note-reading knowledge

  Using trenger here would sound more like the booklet needs..., which is less natural in this context.

Because kunnskap is a common-gender noun, so the adjective takes the common singular indefinite form god.

Compare:

• en bil → en god bil
• et hus → et godt hus

Here the head noun is kunnskap, not note. In the compound notekunnskap, the last part decides the grammatical gender.

So:

• (en) kunnskap → god kunnskap
• therefore god notekunnskap

If the noun were neuter, you would expect godt instead.

Because notekunnskap is being used in a general, uncountable sense.

Norwegian often leaves out the article with abstract or mass nouns when speaking generally:

• Han har god erfaring = He has good experience
• Dette krever tålmodighet = This requires patience
• Noteheftet krever god notekunnskap = The booklet requires good note knowledge / good note-reading skills

So this is not talking about one specific piece of knowledge, but about the skill in a general sense.

It is a compound noun:

• note = note
• kunnskap = knowledge

Together, notekunnskap means something like:

• knowledge of musical notes
• knowledge of musical notation
• note-reading ability
• music-reading skills

The exact English wording can vary, but in practical terms it refers to being able to understand or read notes/music notation.

Norwegian very often combines nouns into one word. This sentence has two good examples:

• noteheftet
• notekunnskap

A helpful rule is: the last part is the main noun, and the earlier part modifies it.

So:

• notehefte = a kind of hefte
• notekunnskap = a kind of kunnskap

This is why:

• notehefte takes the gender of hefte
• notekunnskap takes the gender of kunnskap

This is a very common feature of Norwegian, and it is often different from English, where we might write separate words.

Because this is a normal Norwegian main clause, and the usual word order is:

subject + verb + rest

So here:

• Noteheftet = subject
• krever = verb
• god notekunnskap = object / what is required

This is the standard pattern for a simple statement.

Not with the same meaning.

• Noteheftet krever god notekunnskap means the booklet requires good note-reading skill.
• If you used er, you would need a completely different structure, such as:
  • Noteheftet er vanskelig = The booklet is difficult
  • Noteheftet er for dem med god notekunnskap = The booklet is for those with good note-reading skills

So krever is important because it expresses a requirement.

It is an adjective.

It describes the noun notekunnskap:

• god notekunnskap = good note knowledge / good note-reading skill

An adverb would describe a verb, adjective, or another adverb instead. That is not what is happening here.

Then you would use the indefinite form:

• Et notehefte krever god notekunnskap.

Compare:

• Et notehefte = a note booklet
• Noteheftet = the note booklet

So the original sentence is definite, while this version would be indefinite.

It sounds neutral and factual. It suggests that the material is not for complete beginners and that you need a certain level of ability to use it well.

So the feeling is something like:

• This booklet assumes you can already read notes fairly well
• This material requires good knowledge of musical notation

It does not sound emotional or dramatic; it just states a requirement.