This is a longitudinal study of a child's acquisition of Mandarin phonology between the ages of 1;2 and 2;8. During this period, the child was much less verbal than many children reported in other child phonology studies. The study consists of two parts. The first part is a description of the child's "proto-language," in which he used sound-meaning correspondences of his own invention for communicative purposes. It was found that both the segmental forms and the pitch contours of different "proto-words" correlated with their communicative functions. The second part deals with the child's phonological development following the switch to words based on adult models. Although the child produced very little spontaneous speech, he readily imitated, and the forms of his imitations were subject to strong constraints on the co-occurrence of syllables within words. Specifically, the child favored words whose syllables were identical to each other or at least similar phonetically. The second section also documents the phonetic and phonological aspects of the child's acquisition of aspiration in syllable-initial stops and of the fricative system. (Author/NCR)