There are two types of questions in English grammar: wh-questions and yes-no questions. Wh-questions start with a wh-word like who, what, when, where, why, or how and the format is wh-word + auxiliary verb + subject + verb + object. Yes-no questions can be answered with yes or no and the format is auxiliary verb + subject + verb + object. The document provides examples of each and an exercise to practice forming questions by inserting a wh-word into sample sentences.