I investigate the Intervention Effect in Late Archaic Chinese (LAC) and modern Mandarin. In LAC, negation displays the Intervention Effect on wh-phrases. There are two types of wh-items that are subject to the Intervention Effect triggered by negation, namely, wh-arguments and wh-adverbials that are supposed to move to a lower focus position below the negation; and those that have the option to stay in situ. Due to the intervening negative barrier, these c-commanded wh-phrases have to rise to a higher focus position above the negation so as to circumvent the Intervention Effect. I propose that the Intervention Effect in LAC is a consequence of Q-binding as a feature movement of [wh], interacting with movement into the hierarchy of clause-internal positions driven by [Topic] or [Focus] features. By contrast, focus or quantificational phrases do not display the Intervention Effect in LAC. In modern Mandarin, focus phrases, but not negation or quantified structures, impose the Intervention Effect on wh-items; negation, but not focus phrases or quantified structures, imposes the Intervention Effect on temporal wh-adverbials. I also propound three obligatory requirements for the Intervention Effect to take place in LAC, namely, interrogativity of wh-items, the possibility of feature wh-movement, and a hierarchy of clausal positions. Although the Intervention Effect in LAC and modern Mandarin are triggered by different barriers, it always needs to meet the three requirements. Data from both LAC and Mandarin justify previous analyses regarding feature movement.
