Even though student questioning is the key aspect of inquiry learning, students ask very few questions in Science classrooms. This research aimed to increase the number of high-level questions posed by primary students during science lessons. An experiment was designed in which the experimental group was taught about the taxonomy of questions that can be asked by students during a science lesson. The quality of selected student questions was discussed as a whole class throughout the implementation. In addition, the experimental group completed the textbook activities at the end of each section in groups, whereas, the control group finished these activities individually. The experiment lasted for 4 weeks (12 lessons), during the 'Microscopic Organisms and Environment' unit in two 4th-grade classrooms. After completing each section of the unit, student questions were collected. The questions were classified as either low-level or high-level questions. The findings showed that in the experimental group, there were significantly more high-level questions compared to the control group. The questions were longer and more comprehensive in the experimental group. In both groups, as students' achievement increased, so did the number of questions they asked.