I had a very smart German/Australian shepherd mix who understood lots of words. You could tell her to sit while you threw a ball, a stick, and a frisbee, then say, “Okay, go get the frisbee,” and she would return with the correct item. You could tell her to give the frisbee to Jim (a friend, part of her pack) and she would give it to him. You could then say, “Okay, now go get the stick,” and she would fetch the stick and give it to whichever one of her pack members (friends) was specified.
But these are all commands.
She could pick things like “walk” and “creek” out of any conversation, to the point where we had to be careful what we said when talking on the phone. We had to come up with the usual euphemisms for talking the dog for a walk…take the canine for a stroll (she learned that one), take the D for a W, take the wolf-creature for an ambulation (she never learned that one). We had gestures for the common commands like “sit” and “stay.” We taught her to play dead when somebody pointed a finger at her and said “Bang”–that one was always fun–and if somebody asked her, “What does Sandy say,” she would bark. (Sandy being Little Orphan Annie’s dog, of course.) But again, these are all commands. They pretty much also applied only to pack members, which was either anybody she’d met several times or anyone she met once who gave her a sandwich.
If she was sleeping on the hearth and somebody suggested throwing another log on the fire her ears would flip up, because she had just heard something that sounded like “dog.” This is not a command, but she recognized it. If you said anything about dogs, or walks, or lox, or leeks, those ears would tell you she heard it and recognized it as a Word Of Interest. It was only the things she was really keen to do, like a walk to the creek, where we had to be careful, because if she thought anybody was going to the creek she wouldn’t just flip up her ears, she would jump up and go fetch her leash. And those were not commands but simply words that she understood, or thought she did.
I also tried very hard to teach her to say Milkbone, and she tried very hard to say it, but she just couldn’t quite get there. So much for the millions in endorsements.
I’ve had other dogs but they weren’t that smart.