Um. Uh. So. You Know? These inflections, markers of discourse, are latent parts of any oral speech. But filling language with these words has long invited chagrin: people are judged, thought to be inept, dismissed as ineffective communicators, even dumb. But making these sounds, what linguists call “filler words” and “discourse markers,” is indeed critical to speech. Plus, these utterances help to shape conscious responses and even help assert politeness in tricky situations.

Fillers range from repetitive sounds — such as uh, um, eh, hmm — and proper catchwords or discourse markers such as you know, like, anyway, just. As parts of speech, there is no exhaustive list of filler words as they continue to evolve and weave into people’s speech. It’s perfectly acceptable and more common than people like to think.

Linguists note the fillers serve two major functions — cognitive and interactional. From a visceral lens, the filler phrases help to plug in gaps in speech while a person processes information that is complex or heavy. For instance, when you’re sitting in a meeting and someone pitches an idea, an instant “hmm” or “umm” marks the passage of digesting knowledge.

“This is important for the speaker and the listener as well,” Professor Michael Handford, a professor of applied linguistics and English language at Cardiff University, told Olivia Blair at The Independent. “If you did speak how people write people wouldn’t be able to understand you as we can’t process that much information… As speakers we are often aware, if we speak too complexly the listener might not understand. We use these items, pretty unconsciously, to help the person process what we are saying.”

We use these items unconsciously to help the person process what we are saying. “Sometimes you might be racking your brain for the right words because you’re having a mind-blank or you’ve been asked a particularly difficult or technical question. The brain just hasn’t caught up yet,” notes Blair. When an employer throws you a tough question at the job interview, or a stranger walks up to you, these fillers help your brain to play catch up.

Moreover, people who use filler words are also thought to be more conscious of who they are talking to and what they say. In 2014, researchers analyzed speeches of hundreds of participants between 2003 and 2013. “Conscientious people are generally more thoughtful and aware of themselves and their surroundings,” the researchers wrote. “[This shows a] desire to share or rephrase opinions to recipients.”

Instead of processing information in silence, the filler word becomes a signal that we’re planning to say something.

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This also means people who are more conscientious tend to use filler words more often. “Discourse markers, however, were more common among women, younger participants, and more conscientious people. These findings suggest that filler word use can be considered a potential social and personality marker,” the researchers noted. The idea of using filler words assumes a gendered perspective, where women and other gender minorities who use them are naturally thought of as “inefficient” or less eloquent, which may not be the case.

The second function helps to navigate the conversation in a social setting. Filler words help to avoid awkward interactions. Using them may even be considered cordial. “If you invite somebody to a party and they say no without any of those markers they will appear rude probably. If you say ‘um, well, you know, sorry’ it makes it much more polite. They play a really important politeness function,” Handford noted.

Even from a pure linguist sense, people and leaders, in particular, use these sounds to swipe between conversations and even involve more people in the discussion. “So” and “I mean” become easy ways to enter and exit a conversation. “A well-placed ‘so,’ ‘well,’ or ‘actually’ can be an effective tool to break into a conversation (perhaps in the middle of a rambling colleague’s filler words). Simply make sure you are not cutting someone off mid-sentence,” Allison Shapira wrote in Harvard Business Review.

More importantly, filler speech is also an important marker of our personality — signifying our habits, personality, and even our background. Little words are often out of habit, and are used pretty much automatically during our conversations, John R. Schafer, professor at Western Illinois University, noted in Psychology Today. Even uttering “Acha” in Hindi informs the person’s identity.

The gist, then, is using inflections and filler speech doesn’t make someone less smart or a bad speaker. The judgment comes from a place of leadership and communication, and understanding why the person may be using these words can help put these language decorations in perspective.

If anything, filler words signify our humanity, fallibility, and the dynamicity of language. So, you know, it may be best to let people take time to fill their silences.