Manner Modification Across Modalities: Insights from Gesture, Sign, and Spoken Language

Abstract

This dissertation investigates whether event-related modifiers contribute uniformly to interpretation across modalities, with a focus on contrasts between manner and other modifier types, including path and temporal expressions. It combines morphosyntactic analysis with experimental investigation across three empirical domains: Turkish Sign Language (TİD), English (including co-speech gesture), and Turkish. Across these domains, manner expressions diverge from other event-related modifiers and show a distinct interpretive profile under negation and in contrastive environments. First, I develop a morphosyntactic analysis of classifier constructions in TİD, showing that depictive content is grammatically integrated rather than extralinguistic. Crucially, this system isolates the source of the asymmetry: path-only expressions remain acceptable under negation, whereas constructions encoding manner movement show degradation, identifying manner as the key factor. Second, I present controlled experiments in written English and with co-speech gesture examining how path and manner are interpreted under negation. While gestural contributions degrade under negation, they do not reproduce the path-manner asymmetry observed in TİD. By contrast, linguistic expressions in written English show a clear divergence between path and manner that cannot be reduced to syntactic position, modality, or linear order. Third, I investigate manner adverbials and ideophones in Turkish. The results show that manner expressions across lexical and depictive forms pattern together and diverge from other modifier types. In particular, manner and time adverbials exhibit distinct interpretive profiles under negation and contrastive focus, and ideophones align with lexical manner adverbs, indicating that their behavior is determined by semantic class rather than depictive form. Across these domains, the observed asymmetries are not reducible to modality, syntactic position, or depictive format. Rather, they point to a systematic difference in how manner contributes to event structure. By providing evidence for a distinction between manner and other event-related modifiers, this dissertation contributes to research on event structure, negation, and multimodal composition, and offers new empirical constraints on how event representations are interpreted across modalities.