(En español: Bostezo)
Yawning is when you stretch your mouth open wide. No one really knows why we do it, but it seems to be contagious. If you yawn in class, you'll probably notice a few other people will start yawning, too. Even thinking about yawning can get you yawning. Even though we yawn when we're tired or bored, we hope you didn't yawn while reading about yawning!