Interjections — Those Little Junk Words We Toss Into Conversation — Serve An Important Purpose

“For many decades, linguists regarded such utterances” — mm-hmm, um, huh? and the like — “as largely irrelevant noise, the flotsam and jetsam that accumulate on the margins of language when speakers aren’t as articulate as they’d like to be. But these little words may be much more important than that.” – Knowable Magazine