Relational reasoning, the ability to discern meaningful patterns within a stream of information, is considered a critical capacity for students. However, little is known about how this ability is demonstrated by children of different ages in the context of discourse with a more knowledgeable other. Thus, this study sought to investigate the ways in which 4 forms of relational reasoning (i.e., analogy, anomaly, antinomy, and antitheses) manifested in semistructured conversations between a researcher and child about the form and function of more or less familiar objects. Participants were a nationally representative cross-sectional sample of 61 New Zealand primary and secondary students, divided into 3 grade groups: early (Kindergarten through second), middle (fourth through eighth), and late (tenth through eleventh). Results indicated that children as young as 5 years old were capable of using all 4 forms of relational reasoning in discourse. Furthermore, analysis revealed a curvilinear trajectory in the observed versus expected frequencies of relational reasoning among the groups. Finally, in terms of the individual forms of relational reasoning, analogies and anomalies occupied a smaller proportion of relational talk when children were older, whereas antinomies and antitheses occupied a greater proportion. Implications for research and practice are forwarded.