This study was undertaken to examine the suspicion that a young Greek girl in the short time span of two years had become more fluent in a second language (English) than in her native tongue. To provide a basis of comparison the tests used in this study were also given to the child's older brother who had been in the United States for approximately the same length of time. The girl was 7:1 years old when her family came to the United States and she knew no English at all. Her brother was 14 and had studied English in Greece. Both children took three tests which were measures of lexical dominance: a picture vocabulary test and two word association tests. The data gathered from the study suggest that the girl was losing facility in Greek and was already ahead in performance in English after only two years in the United States. Her brother, on the other hand, seemed to be moving closer to a bilingualism in which he would be able to control both languages with equal facility in appropriate situations. Unlike his sister, however, he would probably always have an accent when speaking English. (Author/CFM)