This study investigated differences in adult-child language interactions when parents and their three-to-four-year old children engage in wordless book reading, text-and-picture book reading and a small-world toy play activity. Twenty-two parents recorded themselves completing each activity at home with their child. Parent input was compared across contexts, focusing on interactive and conceptual domains: use of open prompts, expansions or extensions of children’s utterances, and use of decontextualised (abstract) language. Use of linguistic expansions was greater during book reading than toy play. Parents used open questions and added contingent conceptual information more often when reading wordless books than in both other conditions. Findings suggest that wordless books may combine the benefits of open-endedness and linguistic content based around a narrative. Parents’ use of abstract language also varied by condition. This study extends understanding of the role of activity context in shaping children’s language learning environments.