This qualitative case study examines how four-year-old, Korean–English bilingual children employ Korean and English and Korean honorifics depending on social contexts. With a sociocultural theoretical framework, data were gathered for seven months by observations, interviews, children's artifacts, and audio- recordings, and explored based on thematic and sociolinguistic analysis. The results propose that dual-language acquisition for early bilingual learners is a dynamic social and cultural process, covering multilayered decision-making.