"Why is the king speaking to the queen?"
Translation:Skoro syt dārys dārie ȳdras?
Perhaps because in English we analyze the person being spoken to as an indirect object, and they are trying to demonstrate that the HV verb codes the person being spoken to as a direct object. If we didn’t have an example like this we might be tempted to assign the dative case to the object of ȳdragon when we should actually be using the accusative case. Just a thought.
In future lessons for other cases you will sometimes get sentences that have only nominative and accusative arguments. I think this is done because it is easier for us to decline newly learned nouns if we see them in the less marked (more default) cases first. For example, it might be harder to determine the declension class of a noun if the first time we see it is in the locative or instrumental case compared to seeing it in the nominative case first.