Differential Effect of Formality of Speech Style on Negation Selection in Korean Children and Adults.

Korean negation has two forms, Short-Form Negation (SFN) and Long-Form Negation (LFN), claimed to have different pragmatic meanings in terms of formality. This paper investigated whether Korean 5-year-old children and adults responded to the level of formality in a conversation, using an experimental design in which a puppet asked the participants either formal or informal-style questions. The results showed that adults produced long-form negation significantly more often in the formal condition than in the informal condition, whereas children predominantly preferred short-form negation across both conditions. Generalized linear mixed-effects modelling revealed significant main effects of speech style and age group. Although the interaction between speech style and age group was not statistically significant, planned pairwise comparisons indicated a significant effect of speech style in adults but not in children. These findings suggest that sensitivity to speech style in negation selection is evident in adults but is not yet fully established in 5-year-old children, supporting the view that pragmatic control over negation forms continues to develop during language acquisition.