A STUDY WAS DESIGNED TO EXAMINE THE LINGUISTICS STRUCTURE OF SECOND- AND FIFTH-GRADE TEACHERS' CLASSROOM LANGUAGE USING PROCEDURES THAT HAVE BEEN APPLIED IN RECENT STUDIES OF CHILDREN'S LANGUAGE (LOBAN, 1963 "THE LANGUAGE OF ELEMENTARY SCHOOL CHILDREN" ED 001 875). TEN SECOND-GRADE AND 11 FIFTH-GRADE TEACHERS IN A LARGE, SUBURBAN, PUBLIC SCHOOL DISTRICT WERE ENROLLED AS SUBJECTS IN THE STUDY. THE SUBJECTS WERE WOMEN, HAD A MEAN OF 10.3 YEARS OF TEACHING EXPERIENCE, HAD AT LEAST A BACHELOR'S DEGREE, AND WERE TEACHING IN CLASSROOMS FREE FROM UNUSUAL SITUATIONS. THE CLASSROOM LANGUAGE OF EACH TEACHER WAS UNOBTRUSIVELY TAPE-RECORDED FOR FIVE 40-MINUTE SESSIONS OF REGULAR CLASSROOM ACTIVITY. THE TAPES OF FOUR OF THE SESSIONS WERE TRANSCRIBED AND THE TRANSCRIPTS ANALYZED FOR--(1) NUMBER OF PHONOLOGICAL AND COMMUNICATION UNITS AND NUMBER OF NON-COMMUNICATION UNITS (MAZES), (2) PATTERNS OF STRUCTURE WITHIN THE COMMUNICATION UNITS (WORD ORDER), (3) WEIGHTED SUBORDINATION INDEX TO MEASURE THE USE OF PHRASES AND CLAUSES, AND (4) VOCABULARY DIVERSIFICATION. MAJOR FINDINGS WERE THAT SECOND-GRADE TEACHERS AS A GROUP AND FIFTH-GRADE TEACHERS AS A GROUP DO NOT DIFFER MARKEDLY IN TOTAL NUMBER OF WORDS USED, IN VOCABULARY DIVERSIFICATION, OR IN USE OF SUBORDINATION. ALL MAJOR ENGLISH SENTENCE PATTERNS WERE USED BY TEACHERS AT BOTH GRADE LEVELS. IT APPEARS THAT THE TEACHERS IN BOTH GRADES ARE USING NORMAL ADULT SPEECH PATTERNS THAT ARE NOT RELATED SPECIFICALLY TO ANY DIFFERENCES THAT MIGHT SEPARATE THEM FROM THEIR STUDENTS. THE INVESTIGATOR RECOMMENDS BOTH EXTENSION AND REPLICATION OF THIS STUDY (USING TEACHERS AT DIFFERENT GRADE LEVELS AND CONTROLLING FOR THE CONTENT OF THE CLASSROOM DISCUSSION) AND TEACHER-CHILD INTERACTION STUDIES WITH CRITERION MEASURES UNDER CAREFUL SCRUTINY. (JD)