This study explored inter- and intraindividual immigrant group differences in children's English verbal ability over ages 6-16 in 4 racial/ethnic groups--White Americans, Black Americans, Mexican Americans, and Puerto Ricans (N=2,136). Although all children's mean verbal scores increased with age, immigrant children (except for Black Americans) had lower scores than respective nonimmigrant children. In contrast, immigrant children (except for Mexican Americans) had more persistent verbal growth into adolescence than respective nonimmigrant children. Family resources moderately accounted for immigrant differences in children's mean verbal scores only. The findings support different theoretical models for understanding inter- and intraindividual immigrant differences in achievement. Mexican-American immigrants and Black American nonimmigrants were struggling and merit policy attention.