Talking to the animals
How many words can a dog learn? Have you ever consider what your dog understands as far as human terminology? If you know your dog really well you should be able to see when they understand a word. All of my dogs respond to many, many human words each with their own little visual recognition twist. Luke is again the easiest to read; his responses are more demonstrative making it easier to see if he understands.
All the dogs know everyone's name in the family. I can tell each one to go and see a particularsomeone and they will; of course Jessie is not cannot do this now. I try to teach them new words all the time, even as seniors their learning capacity is large and they are more than willing to give it a try.
When you teach your dog the meaning of our human words it opens up the ability to communicate more readily with them. Take a crazed barking pack; my dogs often go off when someone comes in the door. If I tell them it is just Nicole (one of my daughters) then the barking changes dramatically from guarding to excitement barking. Which is much more tolerable.
If Luke won't eat his meal I will tell him that I put butter in it. He will then go and check out his meal, what a guy. I don't really know how large their vocabulary is but I know they understand alot and I am always teaching them new meanings of words.
Some newer ones are airplane, your grass (I planted a special pot for their eating enjoyment), bird, ice and beach. Each time we do something I explain to them what is going on. "We are going in the car to the park." "Go have a drink of water," "anyone hungry? I'm going to feed the dogs" I constantly talk to the dogs because repetition is the secret to creating an understanding of words that they hear on a regular basis.
Because my dogs understand so many words it can be difficult to tag a new behavior with an associated term as it may mean other things to them already. I have actually gone days before putting a verbal meaning on a behavior because I've had a difficult time finding a word that is new. That or finding a word that I will remember; I really forget easily so it has to be something that will stick in my head as well.
It is nice seeing how much a dog can understand. Talk to your dog; they are listening a lot more than you probably think.