Major parts-of-speech in child language – division in open and close class words

The purpose of this study was to assess rela) tions between major parts)of)speech in 14)to 43)months)old infants. Therefore a division in open class and close class words was made. Open class words consist of nouns, verbs and adjectives, while the group of close class words is mainly constituted of grammatical words such as conjunctions, prepositions and adverbs. The data was collected using the Swedish Early Communicative Development Inventory, a ver) sion of the MacArthur Communicative Devel) opment Inventory. The number of open and close class words was estimated by summariz) ing items from diverse semantic categories. The study was performed as a mixture of longitu) dinal and cross)sectional data based on 28 completed forms. The results showed that while the total number of items in the children’s vo) cabularies grew as the child got older; the pro) portional division in open vs. close class words – proximally 90)10% – was unchanged.