Developmental Cue Weighting in Turkish Sentence Comprehension: Morphosyntactic and Prosodic Sensitivity

This study investigates how monolingual Turkish children (n = 46, ages 6–16) and adults (n = 52, ages 19–57) use morphosyntactic (case marking) and prosodic cues during sentence comprehension, employing a visual world eye-tracking paradigm. Participants interpreted scrambled, verb-medial sentences across four experimental conditions: Neutral-Bare, Neutral-NP1accusative, Neutral-NP2accusative, and Prosody-Bare. Offline comprehension scores revealed that overt accusative case marking was a robust cue for both children and adults, while prosodic cues influenced only adults. Generalised linear mixed-effects models confirmed significant main effects of group and condition, and significant interactions (all p < .001). Eye-tracking analyses showed that both groups used case marking in real time, with effects emerging shortly after the relevant noun phrase, while only adults demonstrated sensitivity to prosodic cues. Age-modelling revealed that sensitivity to prosodic cues increased with age (p < .001), whereas the benefit of case marking decreased slightly. These findings support competition-based cue-weighting models, indicating that Turkish comprehenders first stabilise reliance on reliable morphosyntactic cues, with prosodic sensitivity emerging gradually through development and experience.