Abstract 1. Introduction 2. Beck and Kim's Approach 3. Wh-words as Indefinites 3.1. Relative Clauses and Conditionals 3.2. Interpretation of Wh-Questions 4. Account of Intervention Effects in Wh-Questions 5. Prediction 5.1. Double Object Constructions 5.2. Embedded Wh-Questions 6. Implications for Intervention Effect in Wh-Questions with Other Types of QPs 7. Conclusion References