If you listen to conversations, it is clear that we don't speak in beautifully formed sentences. Spontaneous speech is often vague and full of potential for confusion, not least because people generally come to a topic with different backgrounds and levels of knowledge.
The use of words such 'uh', 'um' and 'like' are often criticised, but it turns out that these filler words are actually essential for efficient communication, enabling two speakers to better understand each other. Without changing the meaning of a sentence, they help us co-ordinate conversations with minimal confusion.
Uh and Um don't replace pauses in a speech, they announce them. The pauses after um are usually about twice as long as those after uh. This suggests that they signal something specific, managing the listener's expectations of what will come next. Pausing mid-sentence without an um or uh to signal a delay is very disconcerting.
Umming and uhing used to be thought to be a sign of deception, with truth tellers not having to come up with a convincing story. Unfortunately, the latest research indicates the opposite. Lots of umming and uhing may signal someone is telling the truth, perhaps because they are making less of a conscious effort to present a front.
All these filler words rely on interpreting another person's mind, which is a highly cognitive skill. It seems that 2 year old children don't respond to filler words but 3 year olds do, suggesting that our understanding of these signals develops along with other verbal and cognitive skills.
UH Using uh before a plot point in narrative seems to improve listeners subsequent recall, while replacing the uh with a cough reduced the recall.
UM Prepares us to be surprised by something new or unfamiliar, a signal that something is changing in the conversation.
HUH Provides essential feedback to speakers, allowing them to clarify a point before a mistake gets out of hand.
MMM Signals our intention to let the other speaker continue with their point.
LIKE Speakers of every language co-opt certain words to punctuate sentences in a way that seems gratuitious. In English, one such word is 'like', but its use may not be as random as it first seems. It may be that it acts as a form of emphasis, based on the participants' knowledge of each other. If you like a band, saying 'the concert was, like, 2 hours away' would mean the concert was worth the effort of a long drive. But saying 'the concert was, like, 2 hours away' if you hate driving, would mean that the distance was too far for you to be willing to go make the effort.
Source: Article Speak like, uh, a pro by David Robson, New Scientist 17 Oct. 2020
