This study is a comparative analysis of the English phonetic systems of 10 fluent adult EnglishFrench bilinguals who acquired their two languages prior to age 8 and who were English-dominant, and of 10 adult English monolinguals. The objective of the study was to determine whether or not early English-dominant bilinguals perceive and produce speech as English monolinguals do. Discrimination and identification tests of synthetic Id-tl and Ii-II continua and speech production tests revealed that the bilinguals' discrimination and production of Id/ and It! and their production of /II did not differ significantly from the monolinguals'. However, the bilinguals' identification of Id-tl and Ii-II and one aspect of their production of Iii did differ significantly from that ofthe monolinguals. The present results indicate that early bilingualism can yield monolinguallike performance in at least one of the bilinguals' languages, but only with respect to certain aspects of the phonetic system. These findings are viewed in light of sound-class distinctions, the perception-production dichotomy, and bilingual phonetic transfer and restructuring.An abiding concern in bilingual research is whether or not individuals who acquire two languages in early childhood possess phonetic systems like those of monolingual speakers. One view is that such individuals (commonly referred to as "early bilinguals") are capable of acquiring complete control of a second-language phonetic system (Lenneberg, 1967;Penfield, 1953;Penfield & Roberts, 1959;Seliger, 1978) and, indeed, that they may be entirely monolingual-like in both of their languages (Baetens Beardsmore, 1986). An opposing view is that early bilinguals experience no particular phonological advantage and, in some respects, may be at a disadvantage compared to late (adolescent or adult) bilinguals (Ekstrand, 1976;Snow & Hoefnagel-Hohle, 1977, 1978. A position intermediate to these is that, although early bilinguals are more likely than late bilinguals to perceive and/or produce their languages in a monolingual-like manner (Asher & Garcia, 1969;Fathman, 1975;Larew, 1961;Oyama, 1976Oyama, ,1982Seliger, Krashen, & Ladefoged, 1975; Tabta, Wood, & Loewenthal, 1981a, 1981b, they still may not function exactly as monolinguals do. For example, in a recent study of Spanish-English bilinguals, Flege and I wish to thank Sheila Blumstein for her ever-helpful advice on and support of this project, Philip Lieberman and Michel Paradis for their indespensable counsel, and John Mertus for his speech programs and valuable assistance. Sincere thanks are also extended to James E. Flege for his insightful comments on an earlier draft and to the editor and reviewers for their pertinent and appreciated comments and suggestions. Any errors or omissions remaining are the responsibility of the author. Portions of this project were funded by a Helen Swallow Richards Endowed Fellowship from the American Association of University Women. Correspondence may be addressed to Molly Mack, Division of English as an Inte...