This is the 2158th most frequent Swedish word.
kvällen
"The evening."
In this sentence, 'kvällen' is used to refer to a specific time period during the day, the evening.
Vi går på bio på kvällen.
We are going to the cinema in the evening.
Here, 'kvällen' is used as a subject of the sentence, describing the atmosphere and conditions of that particular evening.
Kvällen var kylig och stilla.
The evening was cold and quiet.
In this context, 'kvällen' indicates a later portion of the evening.