Filler words are sounds or phrases inserted into speech that don't contribute to the meaning of the sentence. The most common English fillers are "um," "uh," "like," "you know," "right," "so," "actually," "basically," and "I mean." Every language has its own set. They're a universal feature of spontaneous human speech, produced by every speaker on the planet.
Fillers serve a real cognitive function: they give your brain processing time while signaling to the listener that you haven't finished talking. They're not a sign of low intelligence or poor education. Research in psycholinguistics has thoroughly documented that fillers are a normal byproduct of real-time language production, which requires your brain to simultaneously retrieve words, construct grammar, plan ahead, and manage social dynamics.
That said, excessive fillers in professional settings reduce perceived competence and distract from your content. The question isn't whether fillers are "bad." It's whether your filler rate is high enough to create a perception problem. Filler reduction is one of the fastest ways to articulate your thoughts more clearly.
What Counts as a Filler Word?
Any word or sound that appears in speech without adding semantic meaning. Linguists divide them into two categories: filled pauses and discourse markers.
Filled pauses are sounds that occupy silence while your brain searches for the next word:
- Um: signals a longer planning delay
- Uh: signals a brief retrieval delay
- Er: variant of "uh," more common in British English
Discourse markers are words that function as conversational glue, connectors, or hedges:
- Like: approximation, quotative, or pure filler
- You know: listener engagement marker
- Right: seeking confirmation or transitioning
- So: transitioning to a new point
- Actually: hedging or correcting
- Basically: simplification marker (often adds no actual simplification)
- I mean: self-correction or emphasis
- Literally: emphasis (when not used literally)
The distinction matters because filled pauses and discourse markers have different causes and different interventions. Filled pauses respond well to the Pause Swap technique (replace with silence). Discourse markers require habit awareness and conscious replacement.
Why Does Your Brain Produce Filler Words?
Your brain uses fillers as a processing signal during real-time language production. Speaking spontaneously requires executing multiple cognitive tasks simultaneously: retrieving words from memory, assembling them into grammatically correct sequences, planning ahead to where the sentence is going, monitoring what you've already said, and managing social dynamics. When any of these processes needs extra time, your vocal tract produces a filler to hold the floor.
Psycholinguist Herbert Clark at Stanford conducted foundational research showing that "um" and "uh" function differently. "Uh" tends to precede shorter delays (under one second) and signals that the speaker needs a moment for word retrieval. "Um" precedes longer delays (one to three seconds) and signals that the speaker is planning a more complex thought or choosing between multiple options.
This explains why "um" is more common at the beginning of answers to complex questions, and "uh" is more common mid-sentence during routine speech. Your brain is signaling different types of processing difficulty with different sounds.
Other triggers for fillers:
Cognitive load. When the topic is unfamiliar or technically complex, filler rates increase because the brain has more to process. Research shows that filler rates are higher when speakers discuss unfamiliar topics compared to their areas of expertise.
Anxiety. Social pressure and performance anxiety increase filler production. The same speaker who uses 3 fillers per minute in casual conversation might use 8 per minute during a presentation.
Turn-holding. In conversation, silence risks losing your speaking turn. Fillers signal "I'm still talking, don't interrupt." This is a socially functional use, and it's why filler rates are higher in group conversations than in solo presentations.
Why Do People Say "Like" So Much?
"Like" has evolved from a simple comparison word into one of the most versatile discourse markers in modern English. It serves at least four distinct functions, only one of which is pure filler.
Approximation: "It took like three hours." Here, "like" signals that the number is approximate. It's doing real semantic work, similar to "roughly" or "about."
Quotative: "She was like, 'that's amazing.'" This introduces reported speech or thoughts. It replaced "she said" in casual speech for many speakers and has been documented in linguistics research since the 1980s.
Hedging: "It was like... not great." Here, "like" softens a statement, creating distance between the speaker and a potentially negative judgment.
Pure filler: "I was like working on the like project and like realized..." In this usage, "like" carries no meaning at all. It's a habitual insertion that fragments the sentence.
Research from sociolinguists shows that "like" as a discourse marker is more common among younger speakers and women, though it's spreading across demographics. The perception problem is real: listeners consistently rate speakers who overuse "like" as less competent, less professional, and less intelligent, even when the content is identical to a "like"-free version.
The key distinction: occasional "like" as approximation or quotative is linguistically legitimate and socially normal. Frequent "like" as pure filler disrupts flow and costs credibility. If you're using "like" more than 5 times per minute, the pure filler usage is likely dominating.
How Many Filler Words Do People Normally Use?
Average English speakers use 5 to 8 fillers per minute in casual conversation. In professional settings, the threshold for noticeable impact starts around 4 to 5 per minute, and the threshold for credibility damage starts around 6 to 8 per minute.
Benchmarks by context:
- Casual conversation: 5-8 fillers per minute (socially normal)
- Professional meetings: 3-5 fillers per minute (acceptable range)
- Presentations: 1-3 fillers per minute (polished range)
- Below 1 per minute: Very polished, sometimes perceived as overly rehearsed in casual settings
A study published in Advances in Physiology Education found that the critical threshold for professional presentations was approximately 1.3% of total words. For a speaker at 150 words per minute, that translates to about 2 fillers per minute. Above that rate, both credibility and comprehension scores declined.
The Wellspoken Index tracks filler rate deterministically from the transcript: total fillers, fillers per minute, a breakdown by filler type (um, uh, like, you know, right, so), and a timeline showing exactly when fillers occurred during the recording. The type breakdown is particularly useful because it reveals your dominant filler pattern, which determines the best intervention strategy.
Are Filler Words Always Bad?
No. In conversational contexts, moderate filler use serves real social and cognitive functions. The goal isn't to eliminate every filler from every context. It's to reduce them in situations where they undermine your credibility and distract from your content.
When fillers are functional:
- Turn-holding in group conversation. A brief "um" signals you're still formulating. Without it, someone else might jump in.
- Signaling uncertainty honestly. "Um, I'm not sure about the timeline" is more authentic than confidently stating something you're unsure about.
- Softening in sensitive conversations. A slight "I mean..." before delivering difficult feedback creates a conversational cushion.
- Demonstrating spontaneity. Completely filler-free speech in casual settings can sound rehearsed or robotic, undermining trust and rapport.
When fillers are problematic:
- In any context where credibility is being evaluated. Presentations, interviews, client calls, leadership meetings.
- When they exceed 5 per minute in professional settings. At this rate, they become a pattern that draws conscious attention.
- When they cluster. Five fillers spread across two minutes barely register. Five fillers in fifteen seconds signal panic or unpreparedness.
- When they replace substantive pauses. A silent pause before a key point creates emphasis. An "um" before the same point diminishes it.
What's the Difference Between Fillers and Verbal Tics?
Fillers serve a cognitive function (processing time). Verbal tics are automatic repetitions that serve no function at all. The distinction matters for intervention.
Common verbal tics that masquerade as fillers:
- "Right?" after every statement (seeking constant validation)
- "You know what I mean?" repeatedly (insecurity about being understood)
- "At the end of the day" as a sentence starter (habitual phrase, no meaning in context)
- "To be honest" before routine statements (implying other statements aren't honest)
Verbal tics require awareness-based intervention: record yourself, identify the specific tic, and count its frequency. Once you hear it objectively, your brain starts flagging it in real-time, creating the opportunity to pause instead of repeating the pattern.
Key Takeaway
Filler words are natural byproducts of real-time language production, not signs of low intelligence. "Um" and "uh" are filled pauses that buy processing time. "Like," "you know," and "so" are discourse markers with various functions. The issue is frequency and context: below 3 per minute in professional settings is polished, above 5 starts costing credibility. Reduce fillers in high-stakes contexts using the Pause Swap technique, and don't worry about them in casual conversation.
FAQs
Do filler words affect how intelligent I sound?
Research shows fillers affect perceived competence, not actual intelligence. Listeners rate speakers with frequent fillers as less prepared and less authoritative, even when the content is identical to a filler-free version. The perception is about delivery smoothness, not cognitive ability. Highly intelligent speakers use fillers too, especially when discussing complex topics that require more processing time.
Are some filler words worse than others?
Perceptually, "um" and "uh" are more noticeable and more negatively perceived than discourse markers like "so" or "right." "Like" occupies a middle ground: it's very noticeable when overused but less jarring than "um" in isolation. The biggest perception hit comes from clusters of any filler type within a short window.
Do other languages have filler words?
Yes, every language has them. French speakers say "euh." Japanese speakers say "eto" and "ano." Spanish speakers say "este" and "o sea." Mandarin speakers use "nage" and "zhege." The phenomenon is universal because the underlying cause, the need for processing time during real-time speech production, is a feature of all human language.
Track your filler rate, type breakdown, and progress over time with the Wellspoken Index. Download Wellspoken