Abstract
In this paper we report on the case of a 9;8-year-old male, who had been treated for a variety of speech problems over several years, but retained an idiosyncratic set of realizations for target English /r/. His target accent was general Southern USA English, which is fully rhotic in all positions in word structure. Speech data were recorded in a variety of tasks, different situations, and with different interlocutors (including reading aloud, producing word lists, and spontaneous talk). We show how principles from Systemic Phonology and Systemic Functional Linguistics, in particular, the notions of polysystemicity, prosodies, system networks, and register, can be used to describe the patterns found. We also offer an explanation of how these patterns may have arisen.