"The book is mine."

Translation: Boken är min.

[LJLudwig]

When do you use mitt vs. min?

[Super-Svensk]

Min is used for en-words, mitt is used for ett-words, and mina is used for plural.

[wijdan_insk]

And why it uses "min" instead of "mitt" which that means the book doesn't have gender and it's not alive.