Hi Anea! Out of curiosity, how many languages you know? Are most Scandinavians multilingual?
"Know" is a bit... fluent. I tend to separate between how many languages I could read a book in VS how many languages I could order food in... Hah.
I think most Scandinavians learn the neighbor languages during their childhood or teenage years. I learned Danish as a very young child. My dialect is close to Danish and we frequently visited Denmark - it was a three-hour ferry trip away. And Swedish because of all the Swedish children's programs, Emil, Pippi, whatnot.
The three languages Danish, Swedish and Norwegian are quite similar, with some differences in words and pronunciation but not so much you would not get understood when talking your own language. I master all three as such, but prefer to speak my own language when talking to adults. For children I might change completely, depending on their level. But when I have visited Denmark with Swedish friend Josefine, we have all spoken our respective languages without much issues.
There's also hybrids for easing the communication - the most made-fun-of version is "svorsk" (svensk/norsk, AKA Swedish/Norwegian). It's sometimes done on TV and it's rather amusing. I think the best illustration is this candy, as that middle letter is a hybrid between Norwegian/Danish Ø and Swedish Ö. It doesn't make sense in any language, yet A+ for trying.
So yeah, I speak and read Norwegian, Danish and Swedish, albeit I only actually speak the two latter when forced as I feel I'm a character in a TV series when speaking it. I guess the best comparison in English would be to fake a Scottish accent. It's do-able, but doesn't feel natural.
Then there is of course English. Most Scandinavian kids learn it both in school and from the internet. Most are also encouraged to do a second foreign language later on. For me it was French, but I'm somewhere between "can ask simple questions and hope for a simple answer" and ordering food. This is also my approach to German. There is so much similarities to Norwegian I understand a lot of what I read and hear, but I can't form my own sentences.
With a base in English, Germannic languages and a Latin language I can fake my way through many European countries and at least order food, understand basic newspaper headlines and manage my way through non-English websites (for example looking for tickets or info).
As an adult I also tried to learn Greek. The grammar absolutely killed me, but I can read it fine enough (in the pace of a child). I just don't understand a lot of what I read. Hah! I can also - again - order food, say my name, ask how people are doing, understand ticket systems etc.
So yeah... I would say I master four languages - Norwegian, Danish, Swedish and English. I can fake my way through French, German and Greek to some extent, and that also translate into related languages (for example Italian, Dutch). But I could never read a book in those languages, or hold a meaningfull conversation past "Hello, my name is (...), how are you doing?".