This paper gives an account of the transition from one-word to multiword utterances based on the productions of one child from age 1;5.23 to 1;8.15 in spontaneous interaction with her mother. The authors' interpretation of the observed development emphasizes: (1) the initial dissociation and later co-ordination of temporal chaining of elements on the one hand and meaning-relatedness between elements on the other; and (2) the psychological importance of repetition patterns for the change from single-word functioning to meaning-related and temporally-chained multi-word utterances, i.e. utterances that show the duality of patterning characteristic of human languag