In this article, we address relations between lexical and phonological development, with an emphasis on the notion of phonological contrast. We begin with an overview of the literature on word learning and on infant speech perception. Among other results, we report on studies showing that toddlers’ perceptual abilities do not correlate with the development of phonological contrasts within their lexicons. We then engage in a systematic comparison between the lexical development of two child learners of English and their acquisition of consonants in syllable onsets. We establish a developmental timeline for each child's onset consonant system, which we compare to the types of phonological contrasts that are present in their expressive vocabularies at each relevant milestone. Like the earlier studies, ours also fails to return tangible parallels between the two areas of development. The data instead suggest that patterns of phonological development are best described in terms of the segmental categories they involve, in relative independence from measures of contrastiveness within the learners’ lexicons.
