Defining metalinguistic awareness as the ability to reflect on and manipulate the structural features of language, this article examines the hypothesis that the metalinguistic demands of learning to read are shaped by the structure of a language and its associated writing system. The article examines the relationship between phonemic awareness and alphabetic literacy, for example in English, and the role of metalinguistic awareness and non-alphabetic literacy, for example, in Chinese. The ways that bilingualism increases certain aspects of metalinguistic awareness are also examined. The article concludes by noting an instructional implication of the metalinguistic hypothesis: that it is the youngest, least advantaged, least able children who will benefit most from instruction that helps them become aware of the structure of their writing system and its relationship to their spoken language. Contains 16 references. (Author/SR)