Add Yahoo as a preferred source to see more of our stories on Google. fizkes via Shutterstock We all learned to say "thank you" in preschool, but figuring out what to say back can feel a little bit ...

We all learned to say "thank you" in preschool, but figuring out what to say back can feel a little bit tricky. From a simple "you're welcome" to a casual "no problem," knowing how to respond to ...