Background: Oral language has long been acknowledged as a prominent influence on children's reading development. Here, we examine the intersecting contribution of two prominent aspects of oral language - phonology and morphology. We explore this interface by examining contributions from the two dimensions of phonology - phonemic and prosodic - of morphological awareness on children's reading development. Methods: In a longitudinal study, we track the word reading and reading comprehension development of 175 children in Grades 3 and 4 (Time 1) over the course of 11 months into Grades 4 and 5 (Time 2), respectively. At Time 1, children also completed a measure of morphological awareness with items varying across the two intersecting phonological dimensions: phonemic and prosodic changes. Results: We found two unique effects accounting for gains in reading skill over 1 year after controlling for vocabulary, phonological awareness and nonverbal ability, and the appropriate auto-regressor. Gains in word reading skill were predicted by performance on morphological awareness items with phonemic changes. Gains in reading comprehension skill were predicted by performance on morphological awareness items with both phonemic and prosodic changes. Conclusions: These findings point to key differences in the oral language skills that drive the development of word reading versus reading comprehension and encourage us to consider the rich intersection between features of oral language in understanding children's reading development.