Some times you want to show someone that you are interested in him and listening but you can not show it the right way with your body, so here it's some way you can say what you want using your body:
Keep your shoulders squared, arms not touching, this shows you are honest and open to the other person.
Use you hands in conversation, it shows personality and displaying your palms regularly shows you have nothing to hide.
Stare at the person talking, it can be perceived as intimidating and creepy.
