Early science learning and, specifically, the development of scientific process skills are essential for children to understand the natural world around them. Question asking is a valuable tool to help children get information to organise and make sense of their environment. This research aims to find out whether pre-elementary children employ categorical questions on an information-seeking task and at what age they do so. It also intends to examine how this skill evolves just after an educational intervention, and two months later. The participants were 72 children from three early childhood education levels (ECE1: 3-4 years old; ECE2: 4-5 years old; and ECE3: 5-6 years old). Before the intervention, most of the children did not spontaneously ask categorical questions in the proposed task. Teaching this ability to them made them improve it, mainly in the ECE2 and ECE3 groups, and the acquired learning was maintained over time. However, the youngest children have considerable difficulties in using categorical questions. Thus, activities to model children's scientific skills, particularly those involving the formulation of categorical questions, could be included as part of the science teaching-learning process from 4 to 5 years of age.