Listen carefully to a spoken conversation and you’ll notice that the speakers use a lot of little quasi-words—mm-hmm, um, huh? and the like—that don’t convey any information about the topic of the ...

There are approximately 7,000 human languages spoken worldwide. In every one of them, we have expressions for pain, joy, and disgust — often conveyed through short interjections. So, Maïa Ponsonnet ...