From birth, children's interactions with adults are central to their survival, development, health, and well-being. While sensitive and responsive caregiving has long been associated with optimal child development, neuroscience has enabled an understanding of how such experiences influence brain architecture. The serve and return metaphor has been widely adopted by translation and communication initiatives to showcase the type of interactions that drive children's development. In this article, we propose extending the metaphor to serve-return-rally-learn to make explicit the importance of extended, responsive interactions in fostering children's learning. Drawing on the principles of conversation analysis, we explain the interactional components of an adult–child interactional tennis match and explore how adults’ interactional practices can promote rallies to optimize children's learning and development. Houen, Sandy, Staton, Sally, Mulvihill, Aisling and Thorpe, Karen (2026).Serve-return-rally-learn: extending the serve and return metaphor in adult–child interactions. Child Development Perspectives aadaf005. doi: 10.1093/cdpers/aadaf005 | Young children’s brains are built through interactions with adults. High quality interactions between an adult and child in the first five years is at the heart of building the young brain. Our project partners with the State Library of Queensland (SLQ) to harness the potential of their First 5 Forever (F5F) program to support children’s early development. F5F programs bring together program facilitators, children and carers to engage in early literacy experiences. This project seeks to boost F5F facilitators’ confidence, competence and capacity to implement brain building interactions with children and model to carers the interactional strategies that promote optimal child development. To do this we will work with the SLQ and F5F Managers and Facilitators to co-design a suite of resources for professional development purposes that are accessible and enable understandings of optimal interactional strategies for children’s development. The goal is to make every interactional moment matter in a child’s first five years by building and extending the capacity to all adults who interact with children to optimise their development and wellbeing. Researcher: Dr Sandy Houen |