This chapter explores the central role of language in the formation of objective mental reality and explains why the latter’s existence would be impossible without the former. Language comprises three components: words, their mental images (notions), and their meanings in the form of mental constructions—concepts. It exists simultaneously in the physical and mental domains, linking the external world with internal representations. Words are artificial physical objects (sounds or symbols) that are used to denote and designate the world’s entities. The mental images of words replace representations of other objects, denoted by these words, in the mind, enabling both thought and communication. Although language is not a part of objective mental reality, it makes it possible: it is precisely through words and their images that verbal constructions representing reality are formed and transmitted. Language enables the development of verbal thinking in children, who, in the process of acquiring language, simultaneously assimilate the knowledge accumulated by society. Each new word becomes a means of mastering the entities of the world that have been conceptualized by society. Language provides a verbal mode of representing the world and shapes an ethno-specific system of entities, their connections and relations, which influences the structure of objective mental reality. Verbal representations of the entities of the world are disseminated through speech and text, becoming embedded in culture as elements of collective knowledge. Thus, language is not only a means of communication but also the foundation of the human mind and of objective mental reality.