This research examines the content of explanations that 4 English-speaking children gave or asked for in everyday conversations recorded from 2 1/2 to 5 years of age. Analyses of nearly 5,000 codable explanations (identified by markers like why or because) focused on the entity targeted for explanation (e.g., person, animal, object), the explanatory mode of causal reasoning (e.g., psychological, physical), and interrelations between these elements. Children's explanations focused on varied entities (animals, objects, and persons) and incorporated diverse modes (psychological, physical, social-conventional, and even biological reasoning). Children's pairings of entities with explanatory modes suggest appropriately constrained yet flexible causal reasoning. These data are consistent with the hypothesis that young children draw on several complementary causal-explanatory theories to make sense of real-life events.