Forty-eight children, equally divided among three-, four-, and five-year-old groups, were subjects in a study that explored the development and interrelationships among several facets of writing knowledge and reading readiness skills. Three categories of tasks were administered: knowledge of functions, knowledge of forms, and reading readiness skills. The knowledge of functions tasks assessed children's understanding of writing's everyday uses, including writing a list, a letter, and a label. The writing forms tasks assessed dependence on unit features and/or recognition rules, use of production rules, and paper and pencil name writing skills. Reading readiness tasks assessed auditory discrimination, visual discrimination, and letter naming skills. Results indicated that performance scores increased across age groups on all tasks. However, the greatest differences in scores were between the three- and four-year-old groups. Children exhibited the greatest understanding of the practical applications of labeling. Older children appeared more interested in the presence of English letter features than the display's adherence to recognition rules in sorting writing and pseudowriting task cards. All five-year-old children were able to write their first names with a pencil on paper. Significant interrelationships among reading and writing knowledge varied among the groups. (Author/HOD)