Smile
You can easily if someone is smiling for real or fake!
If its a real smile- risorius muscles are used. They pull the lip corners up, there are wrinkles around the eyes; the skin under the brow may go down just a little.
If its a fake smile- the so-called laughter muscles are used, they move the lip corners away from each other; the upper part of the face does not move.

Hands Say A lot
If people hold their hands together, it means they re self confident and it'll be very difficult to convince them for anything they don't believe in!
If you see clenched fists, that means that you can get them into doing something you want them to! They aren't very difficult to convince!

Changing movements of hands
Sometimes people take their hands behind their body. A person will do this gesture only if they are absolutely confident in the moment or if they feel superior. Observe this the next time!

If Stressed!
If men are stressed, they touch their face very often and if women are stressed, they touch their hair, neck and clothes very often!

Body Posture
An erect body posture is the symbol of confidence and a crooked one will often make the other one look unsure of something!

Legs!
Believe it or not but legs are the most honest part of our body! If you see someone suddenly shaking their legs faster, that means the person has become nervous! If you see them suddenly stopping, it means they just got relaxed!

Handshake
A firm handshake shows the person is interested in you!

Emblematic gestures
The gestures should correspond with what the person is talking about. If they do not correspond, that means the person is lying!

Palm In Their Own Forearm!
A palm in their own forearm is a signal that a person is trying to hold in their negative emotions. Observe their expressions carefully and you'll know!