Developmental phonology: 18-29 months.

Utterances of 60 normally developing children, who were within 6 months of their second birthdays, were analyzed for occurrences of phonological processes. The subjects were divided equally into three chronological age groups: (a) 1:6-1:9, (b) 1:10-2:1, and (c) 2:2-2:5. The most prevalent phonological processes evidenced by all three groups were cluster reduction and deviations involving liquids (e.g., gliding). Phonological process percentage-of-occurrence means were considerably lower for the middle group than for the youngest group, with the most dramatic differences occurring for syllable reduction and postvocalic singleton omission. Potential clinical applications of the data for ascertaining what constitutes disordered phonological development in preschool children are discussed, as well as implications for specifying remediation priorities.