Most often, when I'm blogging here, I transliterate my kid's baby talk, because the point is what Isaiah says, not how he says it. But huge effort can sometimes go into figuring out what he's asking or demanding or trying to get across - and when you finally get it right, it's followed, not by gratitude or relief, but condescension. "Thaaaat's it," he says with withering sarcasm, like you're the biggest moron on the planet for not understanding him. Furthermore, you're such an idiot that he can mock you to your face, and you won't even realize it. "Thaaaaaaaat's it." 

Example:

ISAIAH and DADDIO are playing with JAMES the red steam engine and building a very long train, but none of the cars are connecting to JAMES, sadly.

Isaiah: I wonder if James has a pisty mannat.
Daddio: A what?
Isaiah: A pisty mannette. A pisty man net.
Daddio: A what? A "magnet"?
Isaiah: Yeah.
Daddio: James has a pisty magnet?
Isaiah: Yeah.
Daddio: The hell?
ISaiah: A pisty magnet.  A pisty magnet.
[Long pause as DADDIO googles his own brain for an answer] Oh. You wonder if James has a pissy magnet?
Isaiah: Thaaaaaat's it.

The effect is even better when he wants to ride your shoulders or stand on your head. There you are, bending over for the chimp and he's mocking you like you're the neighborhood spaz.