Playing with language is a developmental process as well as a natural and fun one. Engaging in telling, sharing, listening and encouraging jokes, puns, riddles is cognitive enrichment as well as a gratifying one for children.
So learn as many as you can and always have some seasonal jokes/puns/riddles on hand to share with your students.
Q. Why did the picture go to jail?
A. It was framed
Q. What did one stamp say to the envelope?
A. Stick with me and we will go places.
Q. What did one strawberry say to the other strawberry?
A. If yo weren't so sweet, we wouldn't be in this jam!
Q. Why do fish live in salt water?
A. Because pepper makes them sneeze.
Q. What do you get when you cross a snowman with a vampire?
A. Frostbite
Q. What do you call a retired vegetable?
A. A Has-Bean!
Source: Silly Jokes for Silly Kids