A total of 35 children – 20 with expressive specific language impairment (SLI-E) and15 typically developing (TD) peers – were compared longitudinally from 24 to 36 monthswith respect to their production of syllable shapes in 10-minute spontaneous speech samples.SLI-E 24-month-olds predominantly produced earlier developing syllable shapes containingvowels, liquids, and glides. TD 24-month-olds and SLI-E 36-month-olds produced approximatelythe same proportion of syllable types, with the exception of consonant clusters, where TD24-month-olds produced more than SLI-E 36-month-olds. TD children at 36 months showed thegreatest use of syllable shapes containing two different consonants and consonant clusters.Detailed analyses revealed that SLI-E children produced fewer syllable shapes containing finalconsonants, more than one consonant type, and consonant clusters. Furthermore, the childrenwith SLI-E were found to vocalize less often than their TD peers. The possible relationshipsbetween these findings, SLI-E children's concomitant deficits in morphology and syntax,and the implications for diagnosis and remediation are discussed.