Approximately 15% of New Zealand toddlers are ‘late talkers’. These children are at high risk of developing long-term language problems, which may negatively affect education, employment, social development and health. This study will compare brain functioning in late talkers and typically developing children. As late-talking children use more words with similar sound structures, we will focus on brain responses while they say words with varying degrees of similarity. Knowing which aspect of the speech production process leads to problems in these children will support the development of specific and effective treatments, maximising their chance for future success.