Most of us know that people will manipulate others for their own benefit.

Consider the recent example of the founder and CEO of Theranos, ElizabethHolmes. She was determined to protect her company's reputation no matter how much it cost.

According to Karen Donaldson, a communication coach and body-language expert, there are two types of people: those who know what they're doing and those who don't.

People don't want to be on the receiving end of a lie.

Donaldson talked about how her "triangle" method can help you determine if someone is telling the truth and what to do if you suspect they aren't.

1. Pay attention to how they say what they're saying

Donaldson said that to evaluate both verbal and non-verbal signs in your search for the truth you have to read them in clusters. No one sentence or movement will tell you if someone is being honest.

To get an accurate sense of the whole, you have to look at the sum of the parts.

Paying attention to how people say something is important. Take notice of the pace at which someone is speaking.

Donaldson said what we're saying just flows. We remember it because it's true or not. When people's speech patterns start to get erratic, and they're pausing for too long, then have a lot of ideas that come out, that might be them creating stories to suit the occasion.

2. Watch out for telltale head, face, and eye signs

It's another thing to be aware of. A person makes a gesture.

If someone says they didn't do anything but nod their head yes or swear they're telling the truth but shake their head no, those gestures may not line up with what they're saying.

Donaldson said that it was a sign of indecision and lying. Our bodies tell the truth if we control it.

Microgestures like a "lip fold" can also indicate that something isn't quite right.

Donaldson said that someone holding back information is when someone folds in their lips. They don't want to say anything. It's very fast.

Changes in eye-contact patterns are something you want to watch out for. Donaldson said that the research on the belief that someone who's lying won't maintain eye contact is not conclusive.

You have to know what the person's baseline is in order to make an accurate assessment.

Donaldson said that when we blink faster, it's a response to feeling anxious, nervous, not necessarily telling something that's the truth.

3. Be aware of their body and physicality

Take notice of how someone is moving the rest of their body as well.

It's possible that someone is scratching or rubbing their neck.

Donaldson said that the gesture was a self-soothing one. There are different ways to deal with stress. We touch ourselves too much because it's a nurturing gesture. When your parent or guardian calms you down, they rub your hand and back. We do that on our own.

It can be possible to touch or itch the tip of their nose after a speech.

When we're not telling the truth, our nervous system causes sensory symptoms, so our skin and face get itchy, and this is how our body responds to stress. If you ask someone something and they blush, you'll get blood spurting from your face. It's similar to your nose, and that's what makes it itch.

If someone uses their nondominant hand too much while they're talking to you, that could mean that what they're saying isn't true.

Donaldson said that if someone is using their left hand to speak to you, that's a convincing gesture.

Someone who's quick to change their behavior could be keeping something from you.

"They're sitting on a couch or chair and they're talking with you, then all of a sudden they're moving around," he said. They are at the edge of their chairs. They are sitting back. Their chair isn't comfortable. There needs to be a fix. That exerts nervous energy.

What do you do if you think someone's lying to you?

Donaldson said there are two ways to approach a situation when you suspect someone is lying.

If you're talking to a friend, you might say something like, "Is that true, or did you add something in there?" in order to get their attention.

It can be difiucult if you're talking to someone in a position of power. Donaldson suggests asking the person follow-up questions if they are lying.

Donaldson said to call out someone in private.

It's up to you if you're going to confront a suspected manipulator or not.

If you think someone is lying, you have to decide if you're going to follow through with it or not.

If you don't feel confident enough to confront someone you think is dishonest, what would you do?

Donaldson said that many people think that confidence is an emotion. Confidence is a skill set that we can build at any time. If we decide to, we can take on a confident state. People need to stop waiting to feel confident and act with more confidence.

Donaldson said to stop focusing on other people's reactions.

Donaldson told people to stay committed to speaking up. It has nothing to do with who you are, where you come from, how much you have in your bank account, or how many degrees you have.