Two experiments investigated response tendencies of preschoolers toward yes-no questions about actions. Two hundred 2- to 5-year-old children were asked questions concerning actions commonly associated with particular objects (e.g., drinking from a cup) and actions not commonly associated with particular objects (e.g., kicking a toothbrush). The impact of delay and comprehension of questions were also investigated. Results revealed a consistent developmental transition: Younger children tended to display a yes bias whereas older children did not display a bias unless they faced incomprehensible questions, in which case they displayed a nay-saying bias. Delay shifted children's responses in such a way that "no" answers were given more often. These findings hold important implications regarding the use of yes-no questions with children. (Contains 3 figures.)