The road to negation: A comparative study of five typologically and culturally diverse languages.

The acquisition of negation is a key milestone in early language development that enables children to express rejection, non-existence, and deny propositions. In this study, we ask whether the development of the functions of negation follows a universal trajectory or varies based on language-specific features and environmental input. We investigate the acquisition of negative functions in 10 children (age = 2;00-3;00) across five typologically maximally diverse languages: Chintang (Sino-Tibetan), English (Indo-European), Indonesian (Austronesian), Sesotho (Bantu), and Turkish (Turkic). Our findings reveal language-specific developmental trajectories within our sample. Notable differences include variations in the frequency of in child speech and in the ambient language. A strong correlation emerged between the presence of these negative functions in child-directed speech and their use by children. Across the five languages, children pre-dominantly use declarative negative sentences and begin gradually incorporating imperative forms into their repertoire of negative utterances over time. The emergence of negative questions occurs towards the end of age 2, but remains a minor component of children's negative expressions. The overall pattern observed in our maximum diversity sample highlights the significant role of child-directed input and cross-cultural variation in shaping the developmental trajectory of negative functions.