Input offers and child uptakes: Acquiring mood and modal morphology in Turkish

The present study examines input–output relations in the emergence of verbal affixes that mark modal distinctions in Turkish, a morphologically rich language. Longitudinal naturalistic speech data were analyzed from two girls between ages 1;3–2;6 and their caregivers. Four stages of development were identified. Significant associations between verb inflection and modal notion, observed to be stable across the stages in the input, were noted to develop gradually in the children’s speech. Order of emergence of modal inflections was found to be related to input frequency and transparency of inflectional types, whereas development of inflectional paradigms was observed to be related to inflectional diversity. Conceptual accessibility and pragmatic relevance of the modal notions were considered as child-related factors in this development.