What's cool about this is that book is actually a feminine noun, but in the Norwegian language you can choose to use the masculine articles and endings for female nouns! Example: "The book is (lit. lies) on the table) "Boka ligger på bordet" "Boken ligger på bordet"
Both of these are correct.
It depends a lot on where they're from. Upper-class Norwegians from Western Oslo may speak with two genders exclusively, while someone from Tromsø might use the feminine form for every possible word. Old Norse had three genders, and the masculine and feminine merged into one gender in several European languages, but that process is incomplete in Norwegian. The third gender lives on. We try to teach it where it is most natural to use it.