Between 10 and 24 months of age, children progress from communicating through conventional signals to communicating through symbols in a variety of situations. The present study investigates this transition analysing mother-child communication frames and the child's communicative acts, and tracing the developmental changes in both frames and communicative acts. Four children (2 girls, 2 boys) and their mothers were observed longitudinally and extensively, from 10 to 24 months of age, using a multiple case-study method. Through the detailed investigation of these single cases, clear developmental trajectories were found, showing that conventional frames and representational gestures 'bridge' the transition from attentional to symbolic communication. There were significant differences between dyads and children in the developmental trajectories for several frames and communicative acts. The results not only confirm previous findings on the development of verbal and gestural communication, but provide new insights into the transition to symbolic communication in the second year of life, first because of the use of frame analysis and second because of a focus on individual trajectories in development. Copyright # 2003 John Wiley & Sons, Ltd.Key words: communication; symbols; mother-child frames; developmental transition; multiple case study; longitudinal Between 10 and 24 months of age, children typically progress from communicating through conventional signals (vocal and gestural) to communicating through symbols (words and representational gestures) in a variety of situations.