The purpose of this study was to investigate the language use of 40 children with imaginary companions (IC) and 40 children without imaginary companions (NIC) across two age levels: a younger group aged 4;0–5;11 and an older group aged 6;0–7;11. The study investigated the language of these children by examining their use of adverbial and relative clauses, complement clauses, co-ordinating conjunctions and modal types. The findings indicated that, compared with NICs, ICs used a significantly greater number of adverbial clauses, relative clauses, and and, with their use of but approaching significance. Overall, the results were interpreted as indicating that ICs use more mature language, and this demonstrates enhanced social-cognitive skills. It was concluded that the presence of imaginary companions is positively associated with language use and discourse competency of children.