First Language Acquisition Stages in Indonesian Children: A Case Study

Abstract

This study examines the early stages of first language acquisition in an Indonesian child using Yule’s developmental framework. Employing a qualitative case study design, the study observed a child, referred to as Y, from 9 to 15 months of age in her natural home environment. Data were collected through naturalistic observation, field notes, and documentation of caregiver–child interactions. The findings show that Y’s language development was consistent with early prelinguistic milestones, particularly cooing, babbling, responsiveness to caregiver speech, and emerging sound–meaning associations. During the cooing stage, she produced vowel-like sounds that indicated early vocal engagement. These vocalizations gradually developed into babbling, marked by repeated consonant–vowel patterns such as “da-da,” “ba-ba,” and “ta-ta-ta.” Some forms, including “tata” and “yayah,” appeared in meaningful social contexts, such as responding to family members. However, they are best interpreted as proto-words or prelexical communication rather than fully established one-word utterances. The study concludes that early first language acquisition is a gradual process shaped by biological maturation, caregiver input, and repeated social interaction. The findings highlight the importance of naturalistic interaction in supporting children’s early communicative development