Fredagen translates as the Friday so I was marked as wrong. Why not write "Hun arbejdede ikke om fredag".
That would not be right. It should be the Friday as you write (one incident) or på fredage (if general). This exercise should be reviewed.
"She did not work on the Friday" - I think in Danish one would have to say "She didn't work that Friday": Hun arbejdede ikke den fredag.
Native english speaker here...It's a tricky sentence. I would say "She doesn't work on fridays" or "She's never worked Fridays".
You're right, except that we're in past tense here. So it should be "she didn't work Ftidaye" or "she never worked fridays"
Why not virkede here instead of arbejdede ?
"virkede" does more translate into "to function" rather than "to work". I guess you can figure out why it is not appropriate then?