"Σε ποιον μαγειρεύεις;"
Translation:For whom do you cook?
Hang on... The lesson notes specifically, emphatically stated that the relative pronoun is NOT an interrogative, whereas here it is being used very much as an interrogative object pronoun. Well, semantically, anyway. It conveys the same kind of question as "who are you," for which the relative pronoun would be inappropriate. I've noted below that it's correct, I'm just trying to figure out why, as it's not well explained in the notes. Can anybody help me understand how I'm seeing this wrong?
"Οποίος" (together with all its respective forms) is used as a detailed answer to "ποιος;" (together with all its respective forms).
-Who was that?" = Ποιος ήταν αυτός;
-That was the man I saw yesterday = Αυτός ήταν ο άντρας τον οποίον (more simply put, "που") είδα χθες