Questions & Answers about Jag har en fast plats vid fönstret.
Because plats is a common-gender noun in Swedish, so it takes en, not ett.
- en plats = a place / a seat / a spot
- platsen = the place / the seat
The adjective has to match the noun’s gender and number:
- en fast plats
- ett fast jobb
- fasta platser
So fast stays fast here because that is the common-gender singular form.
Here fast means fixed, assigned, or regular.
So en fast plats usually means:
- a fixed seat
- an assigned place
- a regular spot
It does not mean quick here. Even though English fast often means quick, Swedish fast usually means things like firm, fixed, or stuck, depending on context.