This paper reports the findings of three experiments investigating children’s emerging knowledge of the semantics of information-seeking questions and declarative statements in Mandarin Chinese. Mandarin is particularly revealing about the semantic relationship between questions and statements, because it is a wh-in-situ language where question words appear in the same surface syntactic position in both questions and statements. The non-interrogative meanings that Mandarin-speaking children assign to question words lend weight to a unified approach to the semantics of existential expressions, including Free Choice Expressions, Negative Polarity Items, and disjunction words. When Mandarin question words appear in statements, children interpret them to be the semantic equivalents of existential expressions. The findings, therefore, support the unified approach to the semantics of existential expressions.