Duh!

We were on the way home from church tonight and I asked the boys if they wanted to go by my work. They both shouted Yes! So we did.
As I'm pointing out which building it is Eli asked, "Where do you live in there Mom?"
I said, "Work in there?"
"Yeah, where do you work in there?"
"On the far side, over there."
"Oh."
Then we turn and go by the mall.
Eli says, "When did you work there?"
"Where, the mall?"
"Yeah, when did you work in the mall?"
"Well, I never worked in the mall."
"Well, go work there. Duh!"
"Eli don't say 'duh' to me."
"Is it a bad word?"
"No, it's not a bad word, it's just not good manners."
"Oh."

Sometimes he seems so much older than four! And sometimes I don't realize how things really sound when I say them until I hear them coming from the mouths of my children.