Answer:
If you have me, you want to tell me. If you tell me, you don't have me.
Watches students at the prom to make sure there's no funny business.
Rotten trees and Jack-O-Lanterns have this characteristic in common.
I occur twice in eternity. And I'm always within sight.
An utensil used for bread. Also a paper cutter. Used by a thug to take a life, Or wielded by the tamest wife, When used to spread the butter.
I am a rock group with four members. All dead one was assassinated.
Easy
Animal
Difficult
Food
Funny
Kids
Logic
What am I?