Why do we, like, hesitate when we, um, speak?

For as long as we’ve had language, some people have tried to control it. And some of the most frequent targets of this communication regulation are the ums, ers, and likes that pepper our conversations. These linguistic fillers occur roughly 2 to 3 times per minute in natural speech. So are ums and uhs just a habit we can’t break? Or is there more to them? Lorenzo García-Amaya investigates.