Oral language skills support not only the oral communicative competence itself but also reading skills. However, the development of oral communicative competence has not received the same attention in research as reading or even writing has. The main goal of this study was to examine competence (verbal, paraverbal, and nonvocabulary knowledge were also considered. This quasi-experimental study design, involving an experimental and a control group, comprises a sample of 122 students from two public middle schools located in the North of Portugal, with ages ranging from 11 to 16. Verbal, paraverbal, and nonverbal skills were taught and practiced for seven months. These skills were assessed four times (pre-test, two intermediate measures, and post-test). A vocabulary test was administered as a pre-lary knowledge, being also assessed at the end of the intervention program (post-test). Multivariate and univariate analyses of covariance performances at the end of the intervention, after controlling for the effect of the pre-test results. The results of a Mixed ANOVA showed that there was a significant improvement in the experimental group concerning vocabulary knowledge. These results highlight the importance of practicing speaking skills within educative settings for the developmen communicative competence and vocabulary knowledge.