Infant-directed speech in Argentinian Spanish across the first year of life

Research on language acquisition emphasizes the pivotal role of early linguistic input in shaping children’s development. However, most studies focus on English, limiting linguistic and cultural diversity. We extend prior work by characterizing the lexical and morphosyntactic profile of infant-directed speech (IDS) across the first year in Argentinian Spanish (3–5, 6–8, and 9–10 months). Sixty-four mother–infant dyads, native speakers of Argentinian Spanish with infants aged 3–10 months, participated. Semi-structured play sessions provided a corpus analyzed with CLAN software. Descriptive analyses indicated age-related patterns in Argentinian Spanish IDS. Infants aged 6–8 months received less diverse vocabulary, whereas older infants encountered greater diversity. Older infants heard more verbs, whereas younger ones heard fewer. Infants aged 3–5 months were exposed to fewer closed-class words, contrasting with those aged 9–11 months, who heard more of the closed-class words. There was a decline in the noun/verb ratio with increasing age, while the open-/closed-class word ratio peaked at intermediate ages. The present study both contributes to our understanding of how IDS structure changes during the preverbal period and extends the evidence base for non-English languages. Our results highlight the dynamic nature of maternal speech during the preverbal stage and underscore the value of examining diverse linguistic environments to capture the complexity of language-acquisition processes across different linguistic and cultural contexts.