I was recently in a third grade classroom and was struck by the presence of rules that were posted for how to have a conversation. The poster said, "Each person must contribute to the discussion but take turns talking. Ask each other, 'Would you like to add to my idea?' or 'Can you tell us what you are thinking?' Ask questions so that you understand each other's ideas. Say, 'Can you tell me more about that?' or 'Can you say that in another way?'"
Via Elisa Hergueta, jose antonio gabelas, juandoming