The conscious and unconscious movements and postures by which attitudes and feelings are communicated.
Body language can reveal alot of things about the person you're communicating with.
lets throw some of the signs you should notice.
Eyes: When a person looks directly into your eyes while having a conversation, it indicates that they are interested and paying attention.
People often blink more rapidly when they are feeling distressed or uncomfortable.
Pursed lips: Tightening the lips might be an indicator of distaste, disapproval, or distrust.
Lip biting: People sometimes bite their lips when they are worried, anxious, or stressed.
Crossed arms might indicate that a person feels defensive, self-protective, or closed-off.
Standing with hands placed on the hips can be an indication that a person is ready and in control, or it can also possibly be a sign of aggressiveness.
Crossed legs can indicate that a person is feeling closed off or in need of privacy.
Open posture involves keeping the trunk of the body open and exposed. This type of posture indicates friendliness, openness, and willingness.
Closed posture involves hiding the trunk of the body often by hunching forward and keeping the arms and legs crossed. This type of posture can be an indicator of hostility, unfriendliness, and anxiety.
(from verywellmind.com)