Information Structure, Topic chains and Intervention effects. An interface analysis of the Move/Agree dichotomy in discourse-related dependencies

This article provides an information-structural analysis of discourse-related dependencies across typologically different languages, arguing for the relevance of the Move/Agree dichotomy in accounting for a range of independent interface phenomena. The discussion focuses on Topic constituents, examining their morphosyntactic properties, derivation, intonational realization, position within the functional structure, and role in conversational dynamics. Special attention is devoted to the formation of Topic Chains and to intervention effects as evidence for A′-movement, drawing on both theoretical considerations and experimental data from Italian, Spanish, English, and Chinese. The comparative analysis supports a parametric distinction between Topic dependencies derived through Move and those established via Agree, highlighting the crucial role of the Internal/External Merge asymmetry in the interpretation of discourse-related dependencies.