This document discusses embedded questions, which are questions contained within other sentences or questions. It provides examples of phrases that can introduce embedded questions like "I don't know" and "Do you know." It explains the grammatical structures of yes/no questions and wh- questions when used in an embedded form. Specifically, embedded questions follow statement word order and do not use auxiliary verbs. The document also notes exceptions for certain structures like using an infinitive after question words but not after "if" or "why."