The general goal of this study is to investigate quantitative aspects of lexical development in working-class Black children. The specific aims are to: (1) describe changes that occur over an eighteen month time period in the types of lexical items produced by the subjects in the three age groups; (2) describe changes that occur over an eighteen month time period in the frequency of occurrence of the types of lexical items produced by the subjects in three age groups; and (3) describe changes that occur over an eighteen month time period in the size of lexicons produced by the subjects in the three age groups. the longitudinal and cross-sectional design of the method will require categorizing spontaneous video-taped lexical items produced by 12 children over a period of 18 months. The children were subgrouped according to three age ranges: 1;6 to 3;0 years, 3;0 to 4;6 years, and 4;6 to 6;0 years with an equal number of males and females in each age range. The long-term objective of this study is to expand language development research on Black children. A practical objective is to utilize the results of the proposed study to improve language assessment and language teaching processes for minority children in health-related fields, e.g., child development, special education, and speech and language pathology.