10. They keep saying "literally", "absolutely" and/or "definitely"

Sheena R. Harris, who has a BA in psychology, writes that, “Because lying takes effort, words don't flow as smoothly when someone is telling a lie. This means someone telling a lie has to take frequent pauses to consider the words before they turn them loose.” To give themselves time to think, a liar will often use an overabundance of filler words in their sentences. These words include the commonly heard “uh” and “um,” but can also feature those with more syllables, like “absolutely” and “definitely.”

These word fumbles can also indicate the cognitive overload that occurs when a person lies, signaling their distress as their brain tries to think of the right responses to give credence to the fabrication.

While not a surefire method of detecting lies, delayed speech that features a higher number of filler words and/or fumbling of words is a good indication that someone is being less than truthful.