AN ANALYSIS OF CHILDREN'S WRITTEN LANGUAGE DEVELOPMENT RELATED TO GRADE LEVEL, AGE, AND SEX WAS PERFORMED (1) TO DISCOVER THE SEQUENTIAL STAGES OF LANGUAGE DEVELOPMENT AS REVEALED IN BASIC STRUCTURAL PATTERNS IN WRITTEN COMPOSITIONS OF INTERMEDIATE GRADE CHILDREN AND (2) TO ESTABLISH METHODS AND PROCEDURES AND PROVIDE RESEARCH INFORMATION ON THE GROWTH AND MATURATION OF CHILDREN'S WRITTEN LANGUAGE DEVELOPMENT. COMPOSITIONS FROM 50 BOYS AND 50 GIRLS WERE COLLECTED FOR THE FOURTH, FIFTH, AND SIXTH GRADES FOR A TOTAL OF 300 COMPOSITIONS. THE COMPOSITIONS WERE ANALYZED TO DETERMINE TYPE AND FREQUENCY OF STRUCTURAL PATTERNS WITHIN SENTENCES. ANALYSIS SHOWED THAT THE NOUN-VERB-NOUN PATTERN WAS USED MORE FREQUENTLY THAN ANY OF THE OTHER PATTERNS. THE SIMPLER NOUN-VERB PATTERN APPEARED SECOND MOST FREQUENTLY. ALTHOUGH THE MOST COMPLEX STRUCTURAL PATTERN, NOUN-VERB-NOUN-NOUN, WAS FOUND LESS FREQUENTLY THAN THE OTHER PATTERNS, IT WAS USED BY CHILDREN AT ALL OF THE INTERMEDIATE GRADE LEVELS. FINDINGS SHOWED SIGNIFICANT DIFFERENCES IN THE FREQUENCY OF PATTERN USAGE AS COMPARED TO SEX AND GRADE. (JM)