It’s one of the biggest fears anyone who has ever agreed to meet up with someone on an app has — what if your date is lying to you?

“There are a couple of things you can do in the beginning to test someone,” says Maryann Karinch, the author of the new book “Nothing But the Truth: Secrets from Top Intelligence Experts to Control Conversations and Get the Information You Need.” “You can learn to ask questions on a first date or to someone you just met at a party.”

Karinch is an expert on reading people, literally. A body language and lie-detection expert, Karinch has worked with the Department of Homeland Security and other officials to provide trainings and workshops. 

Wondering how you can start weeding out liars right away? Here are Karinch’s suggestions:

Think about your phrasing: “Ask yes or no questions,” Karinch advises. “Because then you expect a yes or no answer. If he’s repeating the question rather than answering or evading, you need to ask yourself, ‘Why won’t he answer?’”

Watch their reactions: It’s important to also listen to your date’s tone in addition to his or her words. “If she seems measured and relaxed in her tone, you think, ‘She seems pleasant,’” notes Karinch. “But then if, all of the sudden, she gets nervous and her hand goes to her neck when she starts talking about her family, you learn two things. One is that talking about her family makes her stressed and, two, that she touches her neck when she’s stressed.”

Gestures like touching your neck or hair or rubbing your fingers together are called adapters, says Karinch. “We all do them. … Normal people, when they tell a lie, they are under stress — and it leaks out.”

Look for nervous ticks: Karinch says these are some of the more commons gestures people do when they are hiding something:

• Men: Rubbing their hands together, rubbing their legs

• Women: Playing with their earrings or hair, touching their necks

Trust your instincts: Karinch notes that people who have been lied to or cheated on often realize after the fact that there were signs that they overlooked. “We have a lot of these skills already,” Karinch notes. “What we are looking for is glitchy behavior. A lot of times, we ignore signs and signals that would give us important behavior clues. So that gut feeling [you got], you were picking up on something.”

Follow Lakshmi Gandhi on Twitter @LakshmiGandhi.