This study describes the typical course and variability in major areas of communicative development for 228 Swedish-speaking children between 8 and 16 months of age. The assessments were made by parental reports with the Swedish Early Communicative Development Inventories (SECDI) using a semi-longitudinal design. Age-based norms for understanding of phrases, vocabulary comprehension, vocabulary production and use of gestures are described at the 10th, 25th, 50th, 75th and 90th percentile levels. More lexical verbs were found among the first words in comprehension than in production. An extensive variability within individuals in onset and development was found for the assessed skills. The individual differences proved to be stable over 4–6 months. No gender differences were found for comprehension of phrases, total gestures, vocabulary compre-hension, or for vocabulary production. Strong, unique associations were found between total gestures and vocabulary comprehension and between vocabulary comprehension and vocabulary production. In contrast, no unique association was found between gestures and vocabulary production. The results generally concur with those reported for English-speaking American children by Fenson et al. (1993, 1994).