A Japanese 4-year-old with protracted phonological development: the challenge of coronals.

This study examines the phonology of a Japanese four-year-old with mildly protracted phonological development (PPD) as a contribution to a special crosslinguistic issue presenting individual profiles in PPD within the framework of constraint-based nonlinear phonology. Although the child's word structure and vowels were well-established, certain consonant classes presented challenges. Coronal anterior obstruents often showed posteriorization (backing): dorsal stops replaced coronal stops, and with some exceptions, alveolopalatal affricates replaced anterior fricatives and affricates.