This is the 568th most frequent Swedish word.
ff
"Ff" is an abbreviation in Swedish meaning "and onwards" or "following."
In this context, 'ff' is understood as 'fortfarande', meaning 'still' or 'yet'. It implies that the action of reading the book is continuing or has not been interrupted.
Jag ska ff läsa boken i kväll.
I will still read the book tonight.
Here, 'ff' is shorthand for 'fortfarande', indicating the continuity of the plan despite challenges.
Trots regnet kommer vi ff ha picknick.
Despite the rain, we will still have a picnic.
This use of 'ff' also derives from 'fortfarande' to signify that the person continues to hold a specific position.