A study was conducted to investigate the ability of children to determine meanings of derived words that have undergone a pronunciation shift while retaining a close orthographic relationship to their base words. A researcher-designed test was constructed using derived words that had their base word included in a "core list" of words at or below the third grade level. Two forms of the test, a visual form and an auditory form, were developed. The visual form was administered to 105 third and 127 fifth grade students, and the auditory form was given to 94 third and 96 fifth grade students. The relationship of each student's ability to determine meaning and his or her performance on a standardized reading measure was also examined. The results indicated that children could utilize graphic information to determine meanings of derived words. In addition, both third and fifth grade students were better able to discover meanings when the derived words were received visually than when they were received auditorily. The findings also suggested that good readers at both grade levels were better able to utilize lexical information conveyed in the orthography in determining meanings of derived words. (FL)