Communicative development in Swedish children 16-28 months old: The Swedish early communicative development inventory-words and sentences

To describe the development of words and sentences in Swedish children 16-2 8 months old, 900 parental reports on 336 children were analyzed. Subjects were randomly selected from the national birth register, and there was a re sponse rate of 88%. The assessments were made using the Swedish Early Commu nicative Development Inventory-words and sentences (SECDI-w&s). Age-based norms for productive vocabulary, pragmatic skills, grammar skills , and maximum length of utterance (MaxLU) were determined. We describe the development of feedback morphemes, semantic categories, and single words an d tasks. Correlation across measures was significant, and especially strong between vocabulary size and grammar skills. Optimized positive predictive values were high for 25 to 28 month predictions (71%-88%), and vocabulary s cores were found to be of particular predictive importance. No significant gender differences were detected. The clinical relevance of the instrument is discussed.