Questions & Answers about Han er interessert i musikk.
Because interessert is used like an adjective here, not like a main verb.
So Norwegian says:
- Han er interessert i musikk = He is interested in music
This works like English:
- He is tired
- He is happy
- He is interested in music
Even though interessert originally comes from a past participle, in this sentence it functions as an adjective, so it goes with er.
No. Interessert means interested, not interesting.
- interessert = interested
- interessant = interesting
So:
- Han er interessert i musikk = He is interested in music
- Musikk er interessant = Music is interesting
This is a very common learner mix-up.