Umm, all of it? For every time the kid surprises us by understanding what we're saying, there are still approximately one million times where our obviously incoherent ramblings make no sense to her.
Like when we want her to wait for something. The kid is not fooled at all by this illusion of time; like the world's greatest Buddhist, she's living entirely in the moment. So phrases like, "First finish your carrots, then you can have the Pop Rocks," mean nothing; she wants the Pop Rocks now, dammit. [I'm pretty sure this is a hypothetical example, btw.]
But "We'll get you dressed, and then Mommy takes a shower, and then we'll go out," doesn't stop her from beating against the front door like an unjustly imprisoned Tajik.
D'oh. Maybe I type too slow. While my wife was in the shower, the kid pulled my smelly t-shirt out of my gym bag and tried to put it on. I figured she was playing, so I put it on her [cute in a trashy, Flashdance way--not how you want to see your daughter dressed, incidentally]. But as soon as my wife came out of the bathroom in her robe, the kid beelined for her, grabbed her hand, and pulled her to the door. She's apparently holding us to our word: 1) I'm dressed, 2) Mommy out of the shower. Let's go.
So it turns out she does understand us; she understands that we're big fat liars.