It is well established that learners transfer sounds from their first to their second language when speaking (see Major, 2008, and references therein). Recent work also indicates that learners may transfer their perception of sounds from the first to the second language. In some cases, errors in production and perception are explicitly corrected due to problems with miscommunication. On the other hand, when such errors do not lead to direct misunderstandings, the errors may be left uncorrected, which may lead to fossilization. This article examines a salient characteristic of English-accented Spanish: putting two adjacent vowels in hiatus rather than producing them as a diphthong. Data show that a simple treatment based on direct negative evidence of syllabification can significantly improve learners' knowledge of these Spanish sound sequences.