Language is a valuable instrument of social adaptation, as it enables the individual to communicate with the environment. Language and Communication are closely linked and constitute a unique process that involves the manifestation of the most complex and diverse aspects of the human personality. The concept of bilingualism has changed over time, as has the perspective on its effects on speakers. As with most linguistic phenomena, the best ways to define it are those that represent it as a continuum in which different modalities and degrees of linguistic competence, different modes and ages of acquisition or learning, different attitudes and options of use. In this comprehensive perspective, bilinguals are not only those who from early childhood acquire and use two (or more) languages in a sustained way or who are equally competent in both languages in all contexts and with all interlocutors, but also those who are learning a second language, or even those who understand but are not in the habit of speaking their languages, as happens with many children of second-generation immigrants. Seen from the point of view of individual and group discursive practices, bilingualism is also complex, multifaceted and dynamic, not being reduced to the mere sum of alternating and well-defined languages. In this work, bilingualism is assumed to be the ability to speak two languages proficiently. This topic has gained increasing academic visibility and interest in the field of Educational Psychology. In the present study, we sought to explore and expose the theme of bilingualism, bringing visibility to the importance of psychologists' intervention in education and highlighting the need for a more comprehensive vision in this area. As a methodology, a systematic literature review was used. Initially, we formulated the research question and then established search "strings" for several databases, in addition to creating inclusion and exclusion criteria. At the same time, we apply specific reading filters. Finally, after the criteria, twenty-four articles were included. The main results of the study include the importance of collaboration between psychologists, educators and families to develop inclusive solutions in the school context, especially with regard to bilingualism. When analyzing the results, the relevance of considering that bilingualism has a positive impact on language acquisition, improving the ability to solve linguistic problems, is highlighted. The existence of strategies such as the content and language integrated learning (CLIL) approach assumed central relevance in this study. The promotion of cultural diversity is essential in the aim of creating an inclusive environment that supports linguistic development. Consideration of individual variability in second language acquisition is also crucial. The relevance of using interventions based on the psychology of language with the purpose of preventing social problems such as school violence is highlighted. The importance of promoting bilingualism is to opt for psychological intervention that considers cognitive, emotional and social aspects and takes into account milestones of linguistic development. Bilingualism is crucial in the practice of educational psychology, reflecting the growing linguistic and cultural diversity.

Keywords: Bilingualism, second language, psychological intervention, multiculturalism, CLIL.