Children's developing understanding of language may influence their ability to accurately respond to questions inquiring about their event knowledge (i.e., Why and How Come questions), potentially creating misinterpretations in adult-child communication. The present study examined 120 5-, 7-, and 9-year-old's accuracy in responding to Why and How Come questions about the cause of their behaviors. Children's accuracy improved with age, highlighting a developmental milestone whereby children become highly accurate by 7 years of age. Further, the semantic differences in question type did not influence children's responses, as there were no differences in children's accuracy when answering Why or How Come questions. The findings from this study highlight the developmental shift in children's abilities to answer Why and How Come questions, and thus the importance of considering the age and linguistic abilities of the child when inquiring about their event knowledge.