Possessive lesson notes
The possessive lesson notes seem to disagree with the examples in the lesson. I'm working under the assumption that the notes are wrong regarding the conjugation of Δικό
For example the notes read 2nd person singular (Δικό) σου
But the question reads
Ο σκύλος είναι δικός σου.
It merely looks like the contributors put in the placeholder of (δικό) at some point. They all know the variants of course. They just never got back to fleshing it out. You should leave a report and/or go to facebook, email, whatever works to report it. They will get to it soon enough. Thank you for pointing it out.