We've all received the conventional wisdom that filler words such as "um", "uh" and the especially dreaded "like" have no place in conversation. They make you sound dumb! They diminish your authority! But, according to a linguist, filler words serve an important function, and we shouldn't be so quick to try to banish them from conversation.
N.J. Enfield, professor of linguistics at The University of Sydney and author of How We Talk: The Inner Workings of Conversation, writes in Quartz that filler words can help you hold the floor in conversation. This applies in friendly conversation and workplace meetings alike, where part of conversation is negotiating the transitions between speakers. As Enfield writes, "The cooperative rules of conversation require us to use traffic signals that regulate the flow of social interaction." And filler words are some of those signals.
Unless you're a real jerk, you use the speaker's silence as a cue that they're done with what they're saying, and it's fair to jump in. OK, so now imagine that the speaker has sworn off filler words. They're formulating a thought, figuring out what they want to say, and instead of filling that space, they just pause. Silence. So of course some eager beaver jumps in, taking the silence for an end of the speaker's thoughts. As Enfield puts it:
The filler is a traffic signal that accounts for your delay: "Please wait a moment, I'm not done yet, normal transmission will soon resume." If the other person is cooperating, as people usually are, they will refrain from taking over the floor.
Sure, you could use a more "dignified" filler such as "now", "so" or "well". But linguistic habits are deeply ingrained, and honestly, don't freak out about it.
Enfield does point out that while filler words are useful in conversation, that utility doesn't extend to public speaking. When you hold the floor, you don't have to worry - I hope - about people jumping in whenever you pause. And public speaking carries expectations for more fluency and a sense of command of the material. Even if you're speaking extemporaneously, you want to convey the sense of mastery that the searching-for-your-words signals of filler words can diminish.
You still don't want to pause too much, letting silence stretch on while you find your next thought. To that end, Enfield suggests a fix straight from the heart of why we use filler words in the first place: Slow down. You don't need to keep up with the quick parries of conversation here - you can set the pace. And by making it a slower one, you give yourself the chance to formulate your thoughts. You'll also come across as the relaxed, authoritative speaker that you want to be.