Analyses of interactions between an adult and a one-year-old child are often connected with studying early communicative competences, e.g. the child’s participation in turn-taking sequences, in joint attention, and use of pointing gestures. Infants’ communicative behaviors were studied using a structured observational measure – the Early Social Communication Scales (Mundy et al., 2003) in a study of 358 12-month-old children. An exploratory factor analysis revealed: (i) a distinction between the categories of initiation and response among the behaviors displayed, (ii) simple and complex behavior categories occurring; (iii) the presence within one factor of behaviors fulfilling various functions (e.g. requesting and sharing interest). An analysis of the results showed that communicative competences can be classified according to their level and ignoring their function, and made it possible to suggest modifications to the way in which behaviors are coded on the ESCS and to complement the procedure of studying early communicative competences.