The critical competencies essential for effective human functioning in the modern world encompass communicating proficiently in one's native language. This proficiency not only ensures successful communication but also plays a pivotal role in preserving community bonds, safeguarding national and cultural identities, enhancing personal cognitive development, facilitating a deeper understanding of the world, and nurturing meaningful interpersonal relationships. The contributors draw upon research outcomes from three primary domains: (1) Analysis of the grammatical and lexical system, (2) description of different language varieties and registers and (3) reconstruction of contemporary trends in education language and teaching. In doing so, they contribute to the ongoing study of and reflection on the significance of one's mother tongue in today's society.