This study contributes empirical evidence regarding the central role that gesture plays in the general process of language acquisition. Previous studies have highlighted this factor during the holophrastic stage (12?18 months), how- ever a void exists in relation to the stage immediately following and immediately preceding the appearance of grammatical structures, the two-word stage. A single case longitudinal study was performed using the constant comparative method. Frequency data were obtained, indicating a permanent choice of the oral com- munication modality over the gestural modality, while at the same time a prevalence of bimodal compositions (gesture-vocalization) over oral unimodal compositions was seen. This suggests that bimodal compositions function as a cognitive-communicative procedural antecedent of the exclusively oral composi- tions that will prevail with the arrival of two words before the handling of grammatical structures, in other words, before the (relative) unimodalization of verbal expression. These results subscribe to the non-modularistic theory of language from the role of gesture in the language acquisition process.