This study investigated the relationship between dialect usage and performance on four language tasks designed to reflect features developmental in nature: articulation, grammatical closure, auditory discrimination, and sentence comprehension. Predictor and criterion language tasks were administered to 90 kindergarten, first-, and second-grade children randomly selected from a Northcentral Florida elementary school with a racial group ratio of 40 percent black and 60 percent white. All children were from rural families of low and lower-middle socioeconomic status backgrounds. When the variance attributed to cognitive development and language facility scores was systematically covaried, results indicated that dialect usage was significantly related to receptive performance but not significantly related to expressive performance. This finding bears two interpretations: (1) the basilect speaking child is deficient in comprehending developmental language forms; and (2) he is in addition demonstrating a basic deficiency in comprehending standard dialect. The later interpretation would contend that the kindergarten through second grade basilect-speaking children examined in this study have not as yet acquired the skill of bi-dialectic comprehension, i.e., the ability to translate standard English into their own dialect for processing. The question of dialect interference, then, appears to be a locallizing phenomenon. The amount of basilect used seemingly interferes with some specific language skills, and not with others. (Author/SB)