Let the Right One In (2008)

Other mistake: When Oskar finds the solved Rubik's Cube it cuts to a shot of Eli sleeping, wearing a large shirt/dress. However, this shirt/dress is the same one that she takes from Oskar's mother's closet later on in the movie and therefore, she wouldn't have it yet.

Eli: I'm twelve. But I've been twelve for a long time.

Trivia: At the end of the movie when Oskar is traveling on the train with Eli inside the trunk, and they are tapping Morse Code on the trunk's lid, they are spelling out "P-U-S-S," which means "small kiss" in Swedish.