This study aims to shed a light on children's pragmatic development by examining Mandarin-speaking children's requests in interactions with their parents. It is found that children between 24 and 36 months old appear to use various request forms, primarily with simple imperatives and WANT statements. A closer examination reveals that children prefer to use simple imperatives in activity-based interactions while both primary forms are found in unstructured daily conversations. The findings suggest that children's preference for simple imperatives may be driven by their awareness of parents' cooperativeness in interactional situations. It is thus speculated that simple imperatives and WANT statements may be children's two primal request forms, but they may pivot on one request form when the situation is right.