Idiom understanding in youth: further examination of familiarity and transparency.

School-age children and adolescents (n = 150) enrolled in Grades 5, 8, and 11 were administered a forced choice task of idiom understanding that controlled for idiom familiarity and transparency. Performance on the task steadily improved during the targeted age range and was affected by the factors of interest: Idioms that were higher in familiarity and transparency were easier for students to understand than those that were less familiar and more opaque. The results of this study provide further support for the language experience hypothesis of figurative language development and for the hypothesis that metalinguistic activity, which itself becomes more sophisticated during the school-age and adolescent years, facilitates later language development. The study also suggests certain methodological implications for future research that examines the development of idiom understanding in youth.