In asking good questions of students, teachers are providing a great model for student questioning. But, what are good questions? There is plenty of reading material available on the art of questioning, but one of the best (and the briefest) is the article “The Right Question at the Right Time,” written by Jos Elstgeest and originally published in the book Primary Science: Taking the Plunge (Heinemann 2001). An oldie but goodie, the article explains the different types of productive questions (e.g., attention-focusing, measuring and counting, comparison, action, and problem posing) and provides guidelines for using them effectively. It also offers practical advice on the best ways to respond to reasoning questions (e.g., how and why questions), an essential question type in science but one of the most challenging kinds to address. While the article was written using examples from elementary classrooms, the content is applicable to teachers of all levels, K–college.