IT IS NOT YET KNOWN HOW THE EXTENT OF LANGUAGE DIFFERENCES BETWEEN LOWER CLASS CHILDREN AND TEACHERS WITH MIDDLE CLASS TRAINING AND, FOR THE MOST PART, WITH MIDDLE CLASS BACKGROUNDS, INFLUENCES CLASSROOM COMMUNICATION. AN EVALUATION WAS MADE OF THE EXPRESSIVE LINGUISTIC SKILLS AND SPEECH CONTENT OF CHILDREN OF DIFFERENT AGES, RACES, AND SOCIAL CLASS BACKGROUNDS AND OF THE EXTENT OF WHICH INFORMATION IS SUCCESSFULLY COMMUNICATED FORM TEACHERS TO PUPILS AND AMONG PUPILS. FINDINGS HAVE THE FOLLOWING IMPLICATIONS--(1) CHILDREN DISADVANTAGED BY CONDITIONS RELATED TO SOCIAL CLASS STATUS AND/OR MINORITY GROUP MEMBERSHIP REQUIRE SPECIAL TRAINING IN SUCH LANGUAGE AREAS AS VOCABULARY DEVELOPMENT, GENERAL EASE IN SELF-EXPRESSION LEADING TO LENGTHY BUT MEANINGFUL VERBALIZATION, GREATER EXACTNESS IN SOUND DISCRIMINATION AND IN PRECISION IN THE USE OF LANGUAGE. (2) RESEARCH SHOWS THE CLOSE RELATIONSHIP BETWEEN INTELLIGENCE, AS MEASURED BY STANDARDIZED IQ TESTS, AND LANGUAGE SKILLS. PREVIOUS STUDIES SUGGEST THAT IMPROVING LANGUAGE SKILLS CAN RAISE IQ SCORES. (3) DIFFERENT SUBGROUPS OF FIRST-GRADE CHILDREN TEND TO BE MORE SIMILAR IN THEIR GENERAL LANGUAGE FUNCTIONING THAN ARE SUBGROUPS OF FIFTH-GRADE CHILDREN. IT WOULD SEEM IMPORTANT TO EMPHASIZE DEVELOPMENT AT AS EARLY AN AGE AS POSSIBLE.