Morphological awareness: A key to understanding poor reading comprehension in English.

This longitudinal study examined the performance of poor comprehenders on several reading-related abilities in the late elementary school years. We identified 3 groups of readers in Grade 5 who were matched on word reading accuracy and speed, nonverbal cognitive ability, and age: unexpected poor comprehenders, expected average comprehenders, and unexpected good comprehenders. We compared these groups in Grade 5 and, retrospectively, in Grade 3. The 3 groups performed similarly on phonological awareness, naming speed, and orthographic processing tasks but differed in morphological awareness, even when vocabulary was controlled statistically. Unexpected poor comprehenders performed more poorly than expected average comprehenders in morphological derivation at Grade 5 but not in Grade 3; in contrast, expected average comprehenders performed more poorly than unexpected good comprehenders at Grade 3, but these groups did not differ in Grade 5. Our findings suggest that poor morphological awareness contributes to reading comprehension difficulties and that children with different reading comprehension profiles may learn morphology at different rates. © 2011 American Psychological Association.