Or, maybe I should call this, "How to speak in front of dogs." As a long-suffering dog owner and person interested in language, I have observed that our dogs have rudimentary language skills.
Kate, the very eager and excitable one, is highly alert to every human movement and gesture. From these she is able to infer a great deal about important events that are about to occur, such as meals, walks, and car rides. She also has a limited receptive vocabulary -- words or phrases that she consistently understands. These include: "food, want some food?, sit, lie down, let's go, outside, treat, & walk." Of course, she also knows her own name, and the names of the other pets.
With the addition of appropriate context and tone of voice, she responds appropriately to a wider range of words and phrases. With the right tone of voice (usually profound annoyance or disappointment), she also responds to "no, bad dog, leave it, & out of the kitchen!" As another example, when we are out for a walk, if one of us shouts, "get the squirrel!" Kate will run towards the tree that holds a squirrel and bark frantically, or begin running about looking for a squirrel. However, if we shout, "get the cat," "get the ball," or even "get the wiener," her actions are exactly the same; she begins running about looking for a small critter or object to chase. So in this situation her actual linguistic understanding is quite limited and dependent on context. But as language-using humans, we tend to think that dogs understand the actual words we are saying, when in fact their method of deriving meaning is more holistic.
Our other dog, Sophie, is more sophisticated (ha ha) linguistically. She understands all of the words and phrases described above for Kate, even outside of the expected context, and many more as well. I estimate that her vocabulary is in the range of about 25-40 words/phrases. Also, she is not fooled by ruses like "get the wiener." However, being a terrier, she has stubborn streak, so she may understand but that does not mean that she will comply.
Sophie is the reason that we have had to learn to speak in code when talking in front of the dogs. Sophie can detect the words "walk" and "food" even when they are embedded without emphasis in a normal stream of conversation. Sophie also has learned to recognize some of the phrases and sentences in which these two words typically appear. So as soon as one of us says the words: "want to go for a...", "going to go for a...", or even "go for a ...", Sophie is already prancing with excitement and running to the door, even before having heard the actual word "walk." Because of Sophie, we now say things like: "I am considering ambling with the canines." Or "I think I will march with the bloggies." Or, "Would you care to join me in taking the boggles for a woggle?" The lengths we have to go to try to outsmart our dogs! And I have to admit, more often than not, they see right through us and our little linguistic charades.