The document discusses different types of interrogative clauses and questions. It explains that wh-questions contain interrogative words like who, what, which, or where that can function as the subject, object, oblement, or adjunct of a clause. It also discusses movement versus feature percolation analyses of wh-phrases and provides examples of non-subject wh-questions, subject wh-questions, indirect questions, non-wh indirect questions, and infinitival indirect questions.