Between-Word Assimilation and Syntax in Child Language Development: a Case Study

Previous developmental research has shown that interactions exist between the emergence of connected speech processes and the acquisition of syntax. This study is the first to have investigated these interactions in detail, using a dense data corpus collected for one child, Thomas, over a two-year period, from the age of two to four years. Investigations focused on the emergence of between-word assimilation in constructions containing the auxiliary verbs can and can’t. The methods of research included impressionistic phonetic transcription, quantitative syntactic measures and qualitative syntactic analysis.

The results showed striking parallels between advances in Thomas’s syntactic development and the establishment of between-word assimilation as a phonological phenomenon in his speech. It appears that the development of assimilation as a connected speech process (CSP) was directly dependent on Thomas’s acquisition of those constructions which provide potential phonetic environments for assimilation to occur. A clear developmental trajectory for the acquisition of assimilation in constructions containing can and can’t was found. This trajectory can be expressed as a phase model, comprising assimilation emergence, establishment and reduction phases.

The impact of maternal input on Thomas’s assimilation was also investigated. It was found that cumulative exposure to assimilation over time was important in Thomas’s acquisition of assimilation. Thomas’s developmental patterns of assimilation and syntax are interpreted within the framework of a usage-based, constructivist approach to language acquisition.