This study examines the role that voiced stop spirantization plays in the acquisition of English/b d g/ and /dgr;/ by native Spanish speakers. The results of a data-based experiment show that accuracy in English pronunciation is hindered by native language transfer, including the transfer of spirantization and LI syllable structure constraints. Furthermore, the suppression of spirantization is not achieved at an equal rate for all voiced stops: /d/ is spirantized the least often. It is proposed that the phonemic value of /δ/ in English contributes to this disparity. An examination of the L2 pronunciation of /δ/ further reveals that learners do not assign phonemic status to /δ/ in all contexts; it is acquired in postvocalic position first and only more gradually acquired elsewhere.