Spontaneous speech samples from children during the period of transition from one word to multi-word utterances in interaction with their French-speaking mothers were explored in order to study the appearance and development of functional changes in their use of language. Two types of such change were noted in the longitudinal records of four children when they were still essentially one-word speakers: the beginnings of references to the past, and the appearance of explanations and justifications, especially in communicative situations of request and refusal. The co-appearance of these behaviours is discussed in relation to two more general developmental changes: a detachment from the immediately perceptible situation linked to a further elaboration of the signifier-signified relation, and a socio-cognitive development leading to a view of the interlocutor as an alter ego, as a person whose psychological states may be different from the child's ow
