interiectio

Interiectio, in Latin grammar, denotes a part of speech comprising words and short phrases used to express a speaker’s emotions, attitudes, or immediate reactions rather than to convey propositional content. Interjections are typically exclamations, cries, or greetings that stand outside the main syntactic structure of a sentence and are usually not inflected or integrated into subject–predicate relations.

Functions of interiectio include signaling surprise, pain, joy, hesitation, or attention, and they can help manage discourse by indicating stance or addressing the listener. In writing, interjections are often set off by punctuation such as exclamation marks and may appear at the beginning or end of a clause without altering the surrounding syntax.

Historically, Latin grammars such as Donatus and Priscian treat interiectio as a distinct part of speech. Latin examples include expressions of pain or wonder such as heu (alas), eûge (hurrah), or simple cries like o and ei. Interjections in Latin are typically non-grammatical, vary in form, and occur in prose, poetry, dialogue, or dramatic situations to convey affective or perceptual responses.

In modern linguistic description, interjections are recognized across languages as a class separate from content words like nouns and verbs. They include a wide range of forms, from phonetic sounds to fixed lexical items (oh, ah, wow, alas) and often rely on prosody and context for interpretation. While they rarely participate in the grammatical architecture of sentences, interjections play an important role in signaling speaker attitude, emotion, and social interaction.