On the oral section of the Master's exam, I often ask a very simple question. If I showed you a poem by Lorca, by Guillén, by Salinas, that you had never seen before, how could you tell who wrote it? This tends to throw some students off. The point is not just to know a particular text, but to know how and why it is typical of its author. You could ask a student what the difference between a sentence of Galdós and Ramón Gómez de la Serna.