Summary

Intervention effects (IEs) refer to the phenomenon where an interrogative wh-expression cannot follow a quantifier or a focus expression. IEs are commonly found in wh-in-situ languages because it is more likely for in-situ wh-expressions to follow quantifiers or focus expressions. Since wh-in-situ in Mandarin Chinese (Mandarin, for short) has been subject to extensive research, it has played an important role in providing the empirical foundation for the research on IEs, based on which different approaches have been pursued. These approaches debate whether the nature of IEs is syntactic, semantic, or pragmatic. They also shed light on related linguistic issues, such as locality conditions, interactions of focus and wh-expressions, and information structure. The present article surveys the empirical and theoretical landscape of IEs in Mandarin, with the goals of providing references and directions for future research.