hmm

Hmm is an interjection used in English to indicate thinking, hesitation, doubt, or mild skepticism. In spoken language it often accompanies a pause while a speaker considers what to say next. In writing it is commonly represented as hmm, hmmm, or hmmm, with variations used to convey tone, length, and emphasis.

As a discourse marker, hmm can help manage spoken interaction by giving the speaker space to think without closing the conversation. It can signal uncertainty about a proposal, invite further explanation, or gently challenge a suggestion. Because it is non-committal, it is usually perceived as polite or non-specific, allowing listeners to supply information or interpretations while the speaker remains non-committal.

Orthographically, hmm is a representation of an audible murmur rather than a discrete lexical item. Spelling and punctuation choices (number of m’s, whether to include a trailing period) convey prosody: longer forms suggest a longer hesitation; a trailing period may add formal tone, while no punctuation implies a quick, casual remark. It appears across many varieties of Modern English and in digital communication.

In technical contexts, HMM refers to Hidden Markov Model, a statistical tool used in sequence analysis and machine learning; this acronym is unrelated to the interjection but shares the same letters. The term hmm is primarily linguistic and sociolinguistic, rather than mathematical or computational.