Sara, I know Spanish, too (I'm a native English speaker) and even knowing Spanish I see the connection between it and Swedish. And regardless of that, even knowing another language makes it so much easier to understand the whys and hows of a new language (ie. adjectives matching in number & gender, word order, different word cases and recognizing them to choose the right verb, etc.) Already I've come across several aspects of Swedish that I don't think I would have easily "gotten" if I didn't know Spanish. I'd have thought "wtf?" haha... and gotten frustrated.
They also murder the people in those books, and brutally rip out the hearts of the readers and leave them to drown in a sea of tears and eternal sorrow while they laugh and fist bump the devil.