What's Wrong With This Picture?

The other night I asked my son if he had homework, to which he replied, nope I just have a paper for you to sign. I told him to go get it so we didn't forget about it. He brought me the bright red paper to sign which proceeded to say..."Your child ... has 1 missing homework assignment...the noun book." "Hmmm...Brennan, is there some homework you should be doing, because it says here that you have a missing noun book." "Oh yeah, that...that's in my backpack." "Is it done?" "Nope, but I'll do it right now." "Yes, my son...good idea."