I don't think they understand whole sentences, but I have noticed, after training many dogs, that with my latest, using that "gooooooood sit" after he sits, seems to speed things up. I think they can connect a couple of short words. Here's another example. I use "off" if I want my Dobe off the couch or bed...whatever. He must get off. Well, now he can apply that "off" command to another context. He has an anoying habit of putting his toy right next to my computer keyboard on the slide out shelf. He stands there and chews it slobbering and bumping my keyboard. So, I tried, "toy off!" And he removed it and chewed it somewhere else. It took a few times for him to figure out that there wasn't anything for him to get off of, so I must mean something else. LOL. Poor dog. I confuse him sometimes, I'm sure. But he's smart and figured that out.
He has been learning "bang, bang, you're dead." He lies down and puts his head down flat on the floor. I say, because I'm still teaching it, "hold it...hoooold it." (because he knows what that means) Then say, "gooooooood dead." LOL. Anyhow, he's getting good at that trick, except he needs to speed up the dying process. It is like slow motion from standing to lying down flat. LOL. How will I fixthat? Any ideas? I want him to drop quickly. Grrrrr.