This study examines first language (L1) English transfer in the acquisition of plural noun semantics in second language (L2) Arabic. Drawing on previous research on the L2 acquisition of plural noun interpretation, the study presents and discusses new production data of specific and generic definite plurals by English-speaking learners of Arabic at beginning (n = 15), low-advanced (n = 15), and high-advanced levels (n = 11). The results from 2 meaning-based elicitation tasks showed that the beginning group heavily transferred their L1 English generic bare plurals in the production of target-like Arabic generic definite plurals. The low-advanced group fluctuated between bare and definite plurals. Only the high-advanced group, who had studied Arabic in an immersion setting combined with very structured classroom instruction, showed considerable stability in their production of target-like definite plurals. A careful analysis of the textbook series the beginning and low-advanced groups were taught from showed that the semantics of plural nouns, and more broadly, the semantics of the definite article, were not explicitly taught. The study concludes that the L1 effects in mapping definite and bare plural nouns to their meanings are exacerbated in the absence of explicit instruction. Further pedagogical implications for teaching form-meaning mappings for articles are discussed.