"It is your egg."
Translation:Det er ditt egg.
You're right that
egget means "the egg" on its own.
egget ditt and
ditt egg are ways to express "your (singular) egg." Whether the noun is definite or indefinite just depends on where you decide to place the possessive in relation to it.
If you put the possessive before the noun—which is generally done for emphasis—the noun should be in its indefinite form (e.g.,
If you put the possessive after the noun, the noun should be in its definite form (e.g.,
I hope you're looking for the difference, not the deference... ;) So, din/di/ditt and min/mi/mitt change with the gender of the noun, and therefore the articles en/ei/et like this: EN mann - mannen DIN, EI kone - kona DI, ET egg - egget DITT. Dine & mine are plural: Eggene DINE. I hope this is helpful.
I "defer" to your information :)
Thank you for the input. I worry some of these basic things I'm struggling to grasp undermine my foundation of the language and make it more difficult for me to learn, so this helps a lot. Vielen dank! (my German is better than my Norwegian)