Sociolinguistic competence deals with the social dimension of language use, of vital importance for teaching. This work delves into sociolinguistic competence level of 380 students from the universities of Jaen, Granada and Oviedo (Spain), identifying the post-test impact of the online “Affective e-learning+” program. Data analysis was performed through a pre-post-test quasi-experimental study with a non-equivalent control group. A descriptive study was conducted, followed by inferential examination. Data were analyzed with the program SPSS v23. The results provided evidence of different levels of initial performance, showing in some cases significant deficiencies. The online program produced significant differences, with a “high” impact with regards to improvement in “registry use and adaptation to the context,” “talking slowly and vocalizing” and improvement in “use of non-verbal language.” It is concluded that there is the need to pay attention to the communicative competence of future teachers, noting the benefits of the program “Affective e-learning+”, designed to improve this competence.