Abstract: Previous studies on topic constructions mainly focus on the features of their topics. Features of their comments and the cognitive motivations of the constructions, however, tend to be neglected. Consequently, no consensus has been reached on the markedness of topic constructions. Taking a cognitive grounding perspective and a typological view of markedness, this paper proposes a feature-cluster study on topic constructions, taking account of structural complexity, functional variation and cognitive complexity of both their topics and comments. This cognitive approach is aimed to counteract the limitations of the previous study.