The aim of our research is the construction of a developmental overview of children’s multimodal skills. The study of the expression of negation in longitudinal data of adult-child conversations is a privileged locus to analyze children’s multimodal skills. A number of authors have observed the transmodal continuity in the expression of negative speech acts. We coded and analyzed all the actions, gestures, vocalizations and verbal productions of a French-speaking and an English-speaking monolingual child from one to three years old. Results indicate that the visual and auditory modalities are first combined into one communicative intent and then used with specific functions, which either reinforce or complement each other.