Further, if ELLs in upper elementary school lack the awareness of derivational
morphology that their native English speaking peers have acquired through greater
exposure to English oral and written language, this may be a source of reading
difficulty. In one of the few studies assessing the morphological skills of ELLs,
Carlo et al. (2004) found that ELLs have lower levels of morphological awareness
than those of native English speakers; however, given the focus of the study on the evaluation of a vocabulary intervention, the specific nature of the relationship
between morphological awareness and reading comprehension in the sample of
ELLs was not investigated. This would be consistent with evidence that many
second-language learners have insufficient depth of vocabulary knowledge to
comprehend sophisticated texts (e.g., August, Carlo, Dressler, & Snow, 2005;
Verhallen & Schoonen, 1998).