The present study examined the relative role played by three cognitive processes — phonological processing, verbal working memory, syntactic awareness — in understanding the reading comprehension performance among 884 native English (L1) speakers and 284 English-as-a-Second-Language (ESL) speakers in sixth-grade (mean age: 11.43 years). The performance of both groups of speakers were comparable on measures of word reading, word reading fluency, phonological awareness, phonological decoding fluency and verbal working memory. However, the ESL speakers lagged behind L1 speakers in terms of syntactic awareness. This study also emphasizes the importance of the three cognitive processes in establishing a common model of reading comprehension across English L1 and ESL reading.