By practicing listening to the other person, noticing details, and paying attention to the gestures and facial expressions of the person, you will be able to understand where you are being told a lie. But all people are different and it happens that lowered eyes during a conversation or a violent reaction to a question can be caused by a type of temperament. Therefore, a professional psychologist will help you understand people more deeply and notice all the important nuances.
The conversation partner tells you a true story, but you are hesitant
☝ Try to learn as much information from him as possible, ask leading questions on the topic, then move on to another topic. After a while, return to this story, ask the same questions and ask to play the story again.
It seems to you that a person is lying when answering questions
☝ You need to try to change the subject, and if the interlocutor is happy to support the idea, exhale with relief, rejoice, then most likely he lied to you. The one who speaks the truth will not understand what the speech is about and will make sure that he is heard.
After answering your question, look at the interlocutor with distrust
☝ If he is not being honest with you, then your gaze will make him feel awkward or insecure. If the interlocutor tells the truth, but your distrust will annoy a little and even infuriate him.
Look at the expression in the other person’s eyes
☝ During deception, a person may look down or they will run. The one who speaks the truth will look straight at you, without embarrassment.
You ask a question and the person answers with a question
☝ Most likely, he evades a direct answer and he has something to hide.
A nervous reaction may follow in response to an uncomfortable question.
☝ The interlocutor may begin to turn around, cough, make sudden movements, fuss. This means that he is preparing to tell a lie.