Interjections are a universal category present in every language, serving to express human emotions, desires, and impulses. When the linguistic analysis of interjections that draw attention in language with their uniqueness in phonetic formations, semantic- grammatical features, and specific communicative functions is handled with a historical perspective it can be observed that these units are a highly debated, overlooked, and undecidable category. The problematic nature of the position of interjections, which are characterized as sentence-words, phonetic indicators, or symbols in language, is closely related to theories about the origin of language. It has been observed that there are two tendencies regarding interjections: inclinations to include them in a larger word class or to grant them an independent word class status. With the increase of human-centered research in linguistics, interjections have also started to be studied in terms of communication, the syntax of spoken language, translation, and foreign language teaching. Due to their significance, this study generally focuses on the definitions of interjections, the history of their examination in linguistics, their positions in language, and evaluations from the perspective of word classes. Specifically, this study examines linguistic units that are included in the category of interjections defined as the ninth word class in Italian. It focuses on the phonetic, morphological, syntactic, and semantic features of Italian interjections, their classification, sources of interjection formation, and their usage.