There's a big section of notes before the lesson that explains it all really well. And "di, din, & ditt" are different possessive forms of "Your" (singular). "di" is feminine, "din" is masculine, and "ditt" is neuter. Eksempler: Mora di, faren din, og barnet ditt - Your mother, your father, and your child.
can someone explain me all those differences between mi, min, mitt and di, din, ditt? please, I really don't understand
Mi is used when that which is owned is grammatically feminine, min with masculine, and mitt with neuter.