Within English early childhood education, there is emphasis on improving speech and language development as well as a drive for outdoor learning. This paper synthesises both aspects to consider whether or not links exist between the environment and the quality of young children's utterances as part of their speech and language development and if so, the nature of those links. In a small-scale case study, data were captured in a natural environment and in indoor and outdoor classrooms. The quality of utterances was analysed using Type/Token Ratios (TTR) analysis. Findings indicate that participant's speech quality differed according to environment. Children's lexical diversity was richer in a natural environment than in indoor and outdoor classrooms, which produced mirrored outcomes. The findings suggest that within the natural environment, where learning is child-initiated, the quality of utterances manifest in ways not found in indoor or outdoor classrooms, where learning is adult led.