This study investigates the similarities and differences between Hong Kong kindergarteners' shyness and social anxiety and their possible relations with social emotional adjustment and the development of receptive language abilities. Data were collected from three kindergartens, with 71 children (mean age = 52.6 months, SD = 7.28; 48% boys) and their major caregivers participating at two time points, six months apart. Findings showed that children's shyness and social anxiety levels were strongly correlated, and both were moderately correlated with children's social emotional difficulties. Interestingly, children's shyness uniquely predicted social emotional difficulties beyond social anxiety, but children's social anxiety did not significantly predict their difficulties beyond shyness. Additionally, neither shyness nor social anxiety were found to be associated with children's Cantonese receptive language skills. Our results highlight the strong similarities between shyness and social anxiety. Given the intricate interplay among the constructs examined in this study, more research is needed to further understand their relations and interactions. This knowledge may help educators to identify appropriate intervention targets to facilitate better language outcomes among shy and socially anxious kindergarteners.