My three year old son comes running up to me in the kitchen while I am doing dishes.
"Mama, I pooped Woody," he says. I turned the water off.
"WHAT?!!" I said, my voice a little high. I was trying to remember the last time I saw the Woody doll in the house.
"I pooped Woody," Zane says again. I look at my child. He doesn't look like he's in pain. Investigating further, I discovered Zane had had an accident ON his Woody underpants. Whew! No trips to the ER today!
If there was ever an argument for the use of prepositions in a sentence, that was it.