You don't have to talk to someone in order to figure out what they're feeling. All you have to do is look at them. Their body language will give their emotions away. If you're not great at reading people, here are a few ways to tell how someone is feeling based on their body language:
If someone is rubbing their hands together, is licking their lips, and is having trouble sitting still, it suggests that they're in anticipation. Of course, it's hard to tell if they're excited or worried over it.