It has been suggested that linguistic proximity affects the ease of acquisition between typologically similar languages, due to the fact that the languages have shared phonological and orthographic properties (Koda, 2008). Thus, a native Hebrew speaker learning Arabic as a foreign language (AFL) would be expected to easily develop linguistic proficiency. This study examined the developmental trajectory for spelling in AFL among native Hebrew speaking adolescents, with specific attention to the development of accurate representations for four novel phonemes and their graphic symbols ([symbols omitted]). The sample included eighth (N = 119), ninth (N = 125), and tenth graders (N = 91). We were further interested in examining the contribution of orthographic as opposed to phonological knowledge to spelling in AFL. Five experimental tasks were created for the study: real word recognition, orthographic sensitivity, auditory discrimination, and dictation of real and pseudowords. Findings for the eighth grade replicated earlier findings for real word spelling (Fragman & Russak, 2010) showing 20% accuracy scores. While spelling accuracy improved by tenth grade, scores remained extremely low (25%). Lexical representations for the four novel phonemes tested were also generally low, with different levels of accuracy for each phoneme. It is possible that the difficulties were the result of interference from shared linguistic elements. Finally, it was found that both orthographic as well as phonological knowledge contribute to real and pseudoword spelling. Implications of these findings are discussed in relation to language teaching policy and pedagogy.