This study examined the effects of first language characteristics on the development of two aspects of English morphological awareness: derivational and compound awareness in English language learners (ELLs) with Chinese or Spanish as their first language. It also assessed the contribution of derivational and compound awareness to word reading in the two groups of ELLs as well as in monolingual English-speaking children. Participants included 89 Spanish-speaking ELLs, 77 Chinese-speaking ELLs, and 78 monolingual English-speaking children from Grade 4 and Grade 7. Results showed that Chinese-speaking ELLs performed similarly to monolingual English speakers on English compound awareness, and monolingual English speakers outperformed Spanish-speaking ELLs. Spanish-speaking ELLs and monolingual children, in contrast, both outperformed Chinese-speaking ELLs on derivational awareness. Another key finding was that in all three groups of children, morphological awareness made a unique contribution to word reading after controlling for nonverbal ability, maternal education, and other reading related variables. These results underscore the influence of first language structure on the development of second language morphological awareness, and the similar contribution of morphological awareness to word reading across monolinguals and ELLs.