The ontology of language is related to the relationship between language, thought and reality, and refers to the very genesis and its constituent elements, called linguistic facts. The article starts from a brief review of the theore tical concepts regarding the essence of language: naturalism / realism, structuralism, neopositivism, E. Coșeriu's conception, creationism. Ontologically, the word is a conventional linguistic symbol, which appears historically, by naming the facts, relationships and phenomena of reality. In this context, it has a meaning by reference to something, as a whole (extension) and a meaning, by content (intention). The functions of language are analyzed: denominative (naming), communication and cognitive formative, the correlation between thinking, logic and language, between syntax and linguistic and logical semantics. In conclusion, some aspects are examined, related to the role of language and scientific language in the didactic discourse. Some applied suggestions for improving language education are made.