This document discusses wh- questions that contain prepositions. It provides examples of informal questions that place the preposition at the end, such as "What does Lucy Cooke write about?" and "Where is she from?". For questions about time, the preposition "at" is omitted. The document also notes that placing the preposition before the question word, such as "With whom does the dog sleep?", is very formal compared to the informal version of "Who does the dog sleep with?".