The interaction between prosodic and segmental aspects of infant representations for speech was explored using the head-turn paradigm, with untrained everyday familiar words and phrases as stimuli. At 11 months English-learning infants, like French infants (Halle & Boysson-Bardies, 1994), attended significantly longer to a list of familiar lexical items than to a phonetically comparable rare list, but 9-month-olds did not. Reversing the stress pattern of the familiar items failed to block word-form recognition in 11-month-olds, although a time-course analysis showed that it delayed the infant response. Changing the initial consonant of English words did block word recognition while change to the second consonant did not. Time-course analyses of both the English and the original French data showed that altering the consonant of the unaccented syllable delays word-form recognition in both languages while change to the accented syllable has a stronger effect in English than in French.