text: Many people all around the world mostly are only with people that they really know personally. You should be able to detect how someone close to you is feeling be how they are acting. If they are not acting normal they obviously something is wrong, so now you need to find out what is wrong. They could detect if they are sad if they are not talking a lot and moslty just sitting around. If they are mad you could just look at their facial expressions when you tell them something and be able to tell if they are mad. So you should easily be able to detect the mood of somebody be the way they are acting.