Three experiments examine the acquisition of word-initial consonant clusters by adult second language learners. Native speakers of Spanish acquiring English participated in a metalinguistic judgment task, a perception task, and a production task. The judgment task indicates that beginning, intermediate and advanced second language learners have an accurate knowledge of English word-initial consonant clusters, with no evidence of transfer from Spanish. However, learners are not able to use that information as effectively as native speakers in perception and production. Transfer does not appear to play a role in learners' perception, though it does in their production. The evidence also provides support for the role of universal developmental factors in second language perception. (Contains 8 tables and 1 note.)