Young children’s ability to distinguish thematic relations: Development and predictive value for early reading

•Longitudinal study of thematic knowledge in young children across school entry.•Co-occurrence based item selection to determine strength of thematic relation.•Homonyms and non-homonyms are judged differently by young children.•Lexical growth fosters ability to reject unrelated words.•Thematic knowledge and storage of distinct meanings are linked to emergent literacy.