When the topic realized as an event argument, the passive form of a VSC becomes unacceptable since its subject NP can neither gain topical features nor be raised to the position.

• 当主题由事件论元充当时,小句的主语无法获得主题特征也不能经历提升;被动化时其名词特征无法核销,故生成的被动句不合格。