It happens after almost every high-profile interview or political debate. Before long, social media is full of clips counting the “ums” and “ers”, mocking awkward pauses, or declaring that a speaker “doesn’t know what they’re talking about.” But those tiny moments of hesitation reveal something quite different: a brain working exactly as it should.
Public figures aren’t judged solely on what they say, but on how they say it. Politicians, celebrities, and executives alike are criticized for using fillers such as um, uh, and you know, or for pausing while they search for the right words. These hesitation phenomena are often taken as signs of uncertainty, low confidence, or even a lack of intelligence.
That criticism reflects a broader obsession with fluent speech. Countless articles, videos, and public-speaking guides promise to help us eliminate filler words, break the habit of “hemming and hawing,” and sound more polished. The message is that hesitations are mistakes.
In reality, they’re anything but. Those tiny pauses and filler words are evidence of a language system working exactly as it should, helping us plan what to say, repair mistakes, and keep conversations running smoothly. (Stollznow, 2026)
Your Brain Is Working Ahead
Speaking may feel effortless, but it’s one of the most demanding things your brain does. As we talk, we’re choosing words, arranging them into grammatical sentences, monitoring what we’ve already said, and planning what comes next, all in a matter of milliseconds.
Sometimes that system needs a fraction of a second to catch up. That’s where hesitation phenomena come in. These include silent pauses, fillers such as um, uh, and er, as well as expressions like well, actually, you know, and like. We might also repeat a word, restart a sentence, clear our throat, or even laugh nervously while searching for the right expression.
Far from being random noise, these moments give the brain a little extra processing time. They help us retrieve words, plan what we’re going to say next, and sometimes catch and repair an error before it slips out. (Dinkar, 2023)
One way to think of fillers is as the spinning loading icon on a computer. The wheel turns while the computer finishes processing. Likewise, an um or uh signals that the brain is still working, quietly buying itself a moment to transform thoughts into speech.
They’re More Than Empty Words
Hesitation phenomena don’t just help speakers; they communicate something to listeners, too. An um or uh often signals that more speech is coming, discouraging interruptions while the speaker gathers their thoughts. A pause can indicate that someone is choosing their words carefully, discussing something sensitive, or expressing uncertainty. These subtle cues help keep interactions running smoothly.
Not all fillers serve the same purpose. Expressions such as you know can invite agreement or check that a listener is following along. Fillers can also soften uncomfortable silences, making speech feel more natural. Rather than making us sound incompetent, they often make us seem more approachable, conversational, and human.
In everyday speech, hesitation is astonishingly common. Studies have found that speakers produce fillers frequently, regardless of how articulate or experienced they are. (Agmon, et al., 2023) They’re not signs of poor communication; they’re simply part of how spontaneous speech works.
The Myth of Perfect Fluency
The expectation that good speakers should never hesitate is a relatively modern one. We hear polished TED Talks, scripted news broadcasts, and carefully edited YouTube and Instagram videos where every pause has been neatly trimmed away. It’s easy to forget that real conversation is naturally messy.
In fact, completely hesitation-free speech can sound strangely unnatural. If someone never pauses, never backtracks, and never searches for a word, it’s probably because they’ve rehearsed extensively or because an editor has removed every imperfection. Of course, there are situations where excessive hesitation may reflect anxiety or a speech disorder, and persistent disruptions deserve appropriate attention. But for most of us, the occasional um, uh, or thoughtful pause is simply evidence that we’re thinking while we speak.
Language isn’t produced by a machine. It’s created on the fly by an extraordinarily flexible human brain. So, the next time an um or like slips into your speech, don’t be too quick to apologize. These tiny words are reminders that your brain is hard at work, carefully transforming thoughts into language in real time.
Read about this topic and more in Karen Stollznow’s new book, Beyond Words: How We Learn, Use, and Lose Language.