This study describes the segmental phonemes of five 4-year-old speakers of Black English, and analyzes both their language development and ethnic characteristics. The study group of Negro children, born and living in Washington, D.C., came from homes that met two of three specified criteria based on the mother's education and family income. The interviews were tape-recorded within a 6-month period after each child had reached his fourth birthday. During the interview, language data was elicited by structuring the 30-45 minute sessions into four productive parts. The results demonstrated that the phonemic system of these children was distinctive. While almost all phonemes were dominated by the conventional Standard English allophones, the presence of unconventional allophones was so pervasive as to effect a markedly nonstandard English dialect, which included both childish and Southern characteristics, as well as others whose identity was not so easily established. The childish patterns included marked instability in the consonant allophones and the presence of "babytalk" patterns. Two of the four Southern patterns were: (1) Southern allophones in the vowel phoneme, and (2) the marked weakening of the phoneme /r/in the final position. The other patterns included pervasive consonant omission in final and medical positions. (Author/LG)