Should I learn Swedish?

I lived in Sweden for many years. I went there with the intention of fitting in, and understanding the culture as best I could. Learning Swedish, not just a little bit, but becoming fluent, was an essential step.

I got an immense amount out of it. A new set of novels to read, a new set of excellent movies to watch, a new set of poetry, a new set of folk songs, a new set of Christmas carols, a new set of public events, private customs and holidays to celebrate, a new set of foods to love, a new set of unusual and delightful places to remember and re-visit, places that tourists never see. And I am still enjoying all that. Note that not everything is global these days. There are always wonderful things that never make it outside of their own country.

So wherever you go to live, learn the language thoroughly so you can get below the surface - there is buried treasure there.

As a tourist you'll be able to get by in Norway, Sweden, and Denmark just fine. You'll also be able to manage as a resident with just English if you live in Copenhagen or another of the larger cities, but... it's not ideal. All documents will be in Danish, you might have important meetings with people who are not fluent in English where it is important that you can understand each other 100% etc., and Norwegian, Swedish, and Danish are the native languages. People will happily accommodate you by switching to English, especially if you're a tourist and at the beginning, but the longer you stay, the more it will be expected of you to learn the language. Say you've been living in Denmark for two years and at a party everyone must still switch languages to accommodate you, it doesn't give a good impression.

Not to say that you must speak the language fluently after 2 years or that you can't switch back to English when necessary, but you need to show people that you're at least trying.

But again, if you don't plan on actually living in Scandinavia, then don't bother learning the languages, you won't need it to visit or get around.

In all three 'core' Scandinavian countries, English is taught well, and it is taught early too, to those of school age... and it has been too for a very, very long time--in terms of that question. Any of these three languages will be easier to 'approach' -- grammatically, that is -- for you, than either French or German .... in terms of *that* question. (So it's good you are good at them...) But for any of them, you will have to decide on your effort and the 'payback' for that effort for later on in your life. (Although we always get a lot more out of any place, Scandinavia included, by knowing even a little bit of the whatever native language(s) are there.) Given what I would estimate would be the effort and the payback on this, I'd certainly say 'yes' to learning Swedish, for the way you see it fitting into your future plans.

If you want to speak Swedish the fact that they know English is irrelevant. Go for it and good luck.