The study attempts to investigate factors underlying the development of spellers’ sensitivity to phonological context in English. Native English speakers and Russian speakers of English as a second language (ESL) were tested on their ability to use information about the coda to predict the spelling of vowels in English monosyllabic nonwords. In addition, the study assessed the participants’ spelling proficiency as their ability to correctly spell commonly misspelled words (Russian participants were assessed in both Russian and English). Both native and non-native English speakers were found to rely on the information about the coda when spelling vowels in nonwords. In both native and non-native speakers, context sensitivity was predicted by English word spelling; in Russian ESL speakers this relationship was mediated by English proficiency. L1 spelling proficiency did not facilitate L2 context sensitivity in Russian speakers. The results speak against a common factor underlying different aspects of spelling proficiency in L1 and L2 and in favor of the idea that spelling competence comprises different skills in different languages.