You may struggle to identify the physical cues that are signs of different emotions, but all humans are born with this ability. Just like any other skill, if you take the time to practice reading people's emotions, you will get better at it.  Observe people in a crowded place (like a mall, nightclub, or park) and try to identify how they are feeling. Try using context, body language, and expressions to figure out who is feeling shy, stressed, excited, and so on.  Read up on body language, especially facial expressions, and how it corresponds to different emotions. Sadness, for instance, is characterized by drooping eyelids, a slight pulling down of the lip corners, and a raised inner brow.  Put on a soap opera and try to identify the emotions the actors are portraying. Use context clues, facial expressions, and body language. Mute the television so you can't get clues from the dialogue. Once you feel you've got it down, move on to more subtle dramas in which the actors use nuanced expressions to convey emotion. You may come off as insensitive because showing emotion makes you feel uncomfortable an awkward. Instead of saying something that might sound stilted or insincere when you see someone is upset, you remain quiet. Accept that it might sound forced when you offer condolences to your friend, "I'm so sorry to hear that...", but know that it will become more natural if you push through and keep trying. To you, sadness may seem pointless, illogical, and self-indulgent. You may wonder why the person doesn't just think through the issue and figure out how to make it better. But emotions are an essential part of decision making, as is logic. Emotions can motivate you to change your life, as emotional discomfort is often an impetus to get out of a rut.  Emotions are essential to making connections and healthy, successful social interactions.  Remember that emotions are simply part of being human. Even if you don't understand them or think they're pointless, be aware that most people don't feel that way. ...

TL;DR in Vietnamese:
Luyện đọc cảm xúc của người khác. Học cách thể hiện sự quan tâm. Hiểu được sự cần thiết của cảm xúc. Chú ý hơn về cảm xúc của bản thân.