The other night, I was reading to Michael (4). He knows his letters and can sound out words pretty well now, but he can be lazy about it. I pointed to a drawing of a rabbit in the book that had bunny spelled out next to it. I asked Michael to read the word.

Michael: "Rabbit"
Me: "No, Michael, sound it out. What's the first letter?"
Michael: "B"
Me: "Michael, what sound does b make?"
Michael: "Buh"
Me: "Good, now what's the word?"
Michael: "Brabbit."

Naturally.