"The couple from Helsinki is at home watching an American series."
Translation:Helsinkiläinen pari katselee kotona amerikkalaista sarjaa.
It's slightly difficult to translate "Helsinkiläinen pari", and I guess they decided to go with "from". It's something like "a Helsinkian couple" really.
Helsingissä asuva pari - a couple that lives in Helsinki
Helsingistä kotoisin oleva pari - a couple that's from Helsinki
I wrote "Helsinkiläinen pari on kotona ja katselevat amerikkalaista sarjaa" which seems like a reasonable alternative, but it was marked wrong. It seems this should also be accepted, since we don't yet have the form "katselemassa," which might be the best fit? Though I may be lost in the Finnish forest . . .