Interjection
Meaning and use

In contrast to typical words and sentences, the function of most interjections is related to an expression of feeling, rather than representing some idea or concept. Generally, interjections can be classified into three types of meaning: volitive, emotive, or cognitive.

While there exists some apparent overlap between emotive and cognitive interjections, as both express a feeling, cognitive interjections can be seen as more related to knowledge of something (i.e., information previously known to the speaker, or recently learned).
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