A study was conducted to delineate the qualitative differences in the language abilities of two disadvantaged groups and one advantaged group of kindergarten and first grade children who were tested on the Illinois Test of Psycholinguistic Abilities. (As part of a larger study, the present report deals only with a part of the pretest phase.) Scores were compared, and an analysis of profile similarities showed that groups were most similar on subtests requiring sequential habits. The greatest performance discrepancies among the groups occurred on the analogs, vocabulary, and grammar subtests. Results indicate that strong syntactic habits are characteristic of higher-level functioning and that sequential language habits are characteristic of more primitive levels of language ability. Two hypotheses are proposed in explanation of the study results: (1) performance on sequential tests is dependent on the relatively fixed capacity of a subject's short-term memory, while other subtests require the ability to "structure" learning which is relatively more dependent upon experience; and (2) since the educationally-deprived children have not developed the higher-level facility with their language, they are relatively free from hypotheses about learning tasks. (MS)