Conversations with a two year old

From a week ago:

Isaac: Garbage trucks stink.

Me: Yes. Yes, they do. They smell bad.

Isaac: We can change them.

Me: Change them?

Isaac: Yes.

Me: Do you mean "change their diapers"?

Isaac: We can change their diapers.

Me: If you say so.

Isaac: Cars don't have poop inside their bellies. Cars just drive.