Results of a longitudinal case study of a monolingual Sesotho-speaking boy show that rule-assigned tone on subject markers is marked appropriately by age two. Underlying tonal representations on verb roots are learned gradually over time, showing an early Default High tone pattern. (Contains 51 references.) (Author)

An autosegmental account of the child's acquisition of grammatical tone in Sesotho, a southern Bantu language, is presented. The following theoretical questions are addressed: (1) When and how does the child figure out that Sesotho is a tonal rather than intonational, stress, or accentual language?; (2) How does the child acquire tonal rules?; and…