DALLAS (WFAA) -- Millions will watch and listen closely to every word spoken in the third and final presidential debate on Wednesday night. But the candidates may also be sharing their thoughts even when they are not the one speaking.

Body language might convey what each candidate is feeling at a given time. Body language expert Leo Cardenas said one of the easiest things to look for are hand gestures.

“If they are nervous about the question or they’re not sure about how to answer something, you will see them either hide their hands behind the podium or hold onto it really tightly,” said Cardenas. In the first two debates, he said Hillary Clinton tended to use hand gestures more so than Donald Trump.

But even the smallest action could signal what a candidate thinks of what the other is saying. Television broadcasts of the first debate often used a split-screen to show both candidates regardless of who was speaking. Viewers might want to look for “micro-expressions” on the face of whichever candidate is listening to the other. Typically, micro-expressions occur when one candidate does not agree with the statement.

“You will see, for example the easiest one to spot, is the half-smile that goes half-way up a little bit. But it is not really a smile, it is just showing contempt.”

Based on the first two debates, Cardenas said Clinton uses micro-aggressions a lot to try and hide or contain anger, but Trump does not mind showing his feelings.

“He likes his micro-expressions to show and he keeps them on his face for quite a long time. So whether he is happy or showing disgust or contempt, it will be very easily identifiable on his face.”

Perhaps the most talked about quirk of the first two debates has been Donald Trump’s sniffling which was apparent in both debates and subject to much chatter on social media. The sniff might actually be a deep breath allowing him to pick his words according to Cardenas.

“That tends to be a tactic used to make sure you measure words correctly,” said Cardenas. “He will take a deep breath, say something, take a deep breath, say something almost like to listen to himself and make sure that the next words he is going to say are correct.”