Questions & Answers about På kvällen är himlen mörk men vacker.
In this expression, på is best translated as “in” or “at”, but it’s really just the standard preposition used with many time expressions in Swedish.
- På kvällen = in the evening / at nightfall (in general)
- På morgonen = in the morning
- På sommaren = in (the) summer
Using i with parts of the day would usually sound wrong or very odd:
- ✗ i kvällen
- ✗ i morgonen
So you should memorize på + [part of day/season] as a pattern for general time:
på kvällen, på natten, på vintern etc.