"The planned research will investigate the early acquisition of argument structure, a crucial example of syntax-semantics linking, in Estonian and cross-linguistic comparison. The project investigates 2 to 5-year-old children’s ability to use information from different cues signalling argument structure, namely word order, case marking, and the discourse context. The rich inflectional system and flexible word order of Estonian provide a sharp contrast to English, on which most studies of syntactic acquisition have been based. Estonian constitutes a missing link in the available cross-linguistic research and an ideal language for examining the coalition of cues used for the semantics-syntax mapping task, due to its robust case-marking system, one-to-many syntax-semantics mappings, and its reliance on word order to convey information structure.The proposed research will analyse both the input speech of caregivers and children’s speech in existing naturalistic ’dense data’ recordings of Estonian, and follow these with experimental studies to probe children’s ability to make sense of the information contributed by linguistic cues. The research will place the analyses of the child’s and caregiver’s speech in a broader context, aiming to further the cross-linguistic research programme tracing various paths to adult knowledge of argument structure. The project proceeds by comparing the acquisition of certain constructions in Estonian with differing structural characteristics. Their development will be traced in recorded data, as well as testing comprehension and production in experiments addressing the issue of how much of children’s emerging linguistic knowledge can be characterised as semantic or syntactic. We will also examine the role of the speakers’ immediate context; the project takes into consideration syntactic, semantic and discourse-level cues to argument structure, leading to a holistic view of the cues children rely on in learning language."