Perfektum is 'har' plus the participle (har bodd, har forandret) and links a past event to now, or leaves the time vague. Preteritum names a finished moment in the past and is required as soon as you say when it happened.
Examples
- Jeg har forandret meg mye de siste årene.
- I have changed a lot in recent years.
- Jeg har bodd i Oslo i ti år.
- I have lived in Oslo for ten years (and still do).
- Jeg flyttet til Oslo i 2015.
- I moved to Oslo in 2015.
- Har du noen gang angret på et valg?
- Have you ever regretted a choice?
The mistake to avoid
Using perfektum with a finished time expression ('jeg har flyttet i 2015') - a stated past date forces preteritum.
Where this fits in
Refleksjoner over livet, Norwegian B2: Reflect on life, values, personal growth, and relationships.