Learn Hardcore Norwegian: Skolen forbyr høye lyder i biblioteket. - The school forbids loud sounds in the library.

Skolen means “the school.” The suffix -en marks masculine/feminine definite singular.
Norwegian often uses the definite form for known institutions (school, hospital, church) when referring to the local/obvious one.
Forms: en skole (a school), skolen (the school), skoler (schools), skolene (the schools).
Here, Skolen refers to the school administration as an institution, not the building itself.

How is the verb forbyr conjugated?

Infinitive: å forby (to forbid)
Present: forbyr (forbids/forbid)
Preterite (past): forbød (forbade)
Past participle: forbudt (forbidden)
Related noun: et forbud (a ban)
Pattern for “forbid someone to do something”: forby noen å + infinitive (e.g., Skolen forbyr elevene å bråke.)

Why is it høye and not høy?

Høy (loud/high) is the base adjective.
Before an indefinite plural noun, adjectives take -e: høye lyder (loud sounds).
Other patterns:
- Singular masculine/feminine: en høy lyd
- Singular neuter: et høyt skrik
- Definite (any gender/number): de høye lydene

Is lyder the correct plural of lyd? What are the forms?

Yes.

Why is it i biblioteket and not på biblioteket?

i biblioteket = physically inside the library room/space (fits rules about silence in that room).
på biblioteket = “at the library” as a place of activity; also very common.
Both are grammatical; i stresses inside the room, på is broader/idiomatic.

Why does biblioteket end in -et?

Is the word order normal? Can I front the place phrase?

Neutral main-clause order is Subject–Verb–Object–Place: Skolen forbyr høye lyder i biblioteket.
You can front the place, but Norwegian keeps the verb in second position (V2):
- I biblioteket forbyr skolen høye lyder.

Does forby take a direct object, or do I need a preposition?

It takes a direct object: forbyr høye lyder (forbids loud sounds).
With a person and an action, use: forby noen å + infinitive.
- Example: Skolen forbyr elevene å lage høye lyder i biblioteket.

Is høye lyder idiomatic, or should I use støy/bråk?

Høye lyder (loud sounds) is fine and clear.
Alternatives:
- støy = noise (often technical/general): Skolen forbyr støy i biblioteket.
- bråk = racket/rowdy noise (colloquial): Skolen forbyr bråk i biblioteket.
- For music: høy musikk (loud music), not plural: Skolen forbyr høy musikk i biblioteket.
- Adjectives for “noisy”: høylytt, støyende.

How would I say “The school forbids students to make loud noises in the library”?

Skolen forbyr elevene å lage høye lyder i biblioteket.
You can also use the verb bråke (to make noise): Skolen forbyr elevene å bråke i biblioteket.

How do I make the sentence negative or turn it into a question?

Negative: place ikke after the verb (and before the object in neutral order):
- Skolen forbyr ikke høye lyder i biblioteket. (“The school does not forbid…”)
Yes/no question: invert subject and verb:
- Forbyr skolen høye lyder i biblioteket?

How would a sign or rule phrased more tersely look?

Any quick pronunciation tips for tough vowels?

ø/øy in høye sounds like a fronted “oy” (round your lips): roughly “HOY-eh.”
y in forbyr is a fronted “ee” with rounded lips.
Skolen ≈ “SKOO-len” (long oo), biblioteket ≈ “bib-lee-oh-TEH-keht.” Dialects vary, but this will be understood.

Would it be wrong to drop the place phrase?