Dogs don’t understand words as a language, in the sense of the meanings of words to humans. Dogs do learn to associate sounds and tones of voice—our rendering of words—with the experiences they have had.

The word “no,” like any other word, carries to your dog the meaning it has occupied in the dog’s life, as part of the dog’s history. You might as well say “Gurp” or whatever other odd sound you can spell with letters, for the entire actual meaning no” as a word has to a dog. Whatever sound you utter, the tone of your voice and the body movements you make at the same time will affect how your dog perceives the sound, just as it does with humans.

For humans, language is innate; it is part of how our brains normally develop. Dogs use body language instinctively—and so do humans. But if a dog’s brain is wired to use words, that wiring does not get the vastly expanded capability that occurs in human infants, toddlers and growing children from the feedback the humans around them give when the child utters the words.

The brain is a marvelous mystery, and it is possible dogs have some word ability, if humans learn how to develop that ability in dogs. To be fair and humane to your dog, though, it is important that you do not hold your dog responsible for understanding the words you say. Give the dog credit when the dog does understand. But make sure that you express your wishes to your dog in forms we can be reasonably sure a dog can understand.

Training that emphasizes the positive and avoids punishment makes it reasonable to play around with words and other potential perceptions to explore just what your dog shows ability to comprehend. Much is being discovered about dogs in this way—and in fact, much has been discovered by such means ever since humans and dogs have been doing things together.

Dogs do a lot of things for humans that we do not fully understand. This includes many of the jobs that working dogs perform every day. People and dogs interact; the people take note of ways and means that effect learning and reliable performance in dogs, they teach them to other handlers, and knowledge of dog training moves forward. We may know that something works in training dogs, but we have only theories as to why it works. This is extremely common in dog training.

Though in many cases we know dependable ways to teach things to dogs, we know far less often just how that training seems to the dog! We don’t even know whether work is viewed by a dog as a vital mission it’s a privilege to perform, or a great big thrilling game! Quite likely, it is one thing on one occasion and the other on another occasion, even for the same dog.

Dogs are far more complicated than was once thought, and more complicated than most people realize. On the other hand, dogs are far from being humans in furry suits with four paws. The world appears different to a dog than it does to a human. From this point of view, consider that one of the first things many humans say to a dog is “no.” What effect is “no” going to have on that dog?

Never Say Never

Many dog trainers tell their students not to ever say the word “no” to their dogs. This practice has merit. Humans assume dogs understand the word in ways they simply don’t. And yet the dog responds, which to the human seems to confirm that (mistaken) belief.

Dogs generally WANT to understand what people are trying to communicate. Some dogs have a genetically bred desire to please humans, and others have had this desire developed in them by dog-savvy human handling. These dogs want to understand you because they want to please you.

Other dogs, some people believe the majority if not all dogs, do not desire to please humans. They simply want their needs met. They want to be fed, have the water dish kept fresh, and otherwise cared for by humans. Whatever you believe about dogs’ desire to please people, you can see that every dog has reason to try to understand us.

When you say “no” to a human, that person has access to other knowledge to figure out what the word “no” means at that moment. The person likely has a sophisticated—very sophisticated, compared to a dog’s—knowledge of human rules and possibly of your own wishes. If the reason for the “no” is to prevent something from being damaged, the person has some understanding of what that damage would mean.

In contrast, dog knowledge of the human world and rules is much more limited. The value of things is a mystery to a dog, because what does a dog know of money? Dogs don’t realize that eating certain things will make them sick or kill them. Sometimes you say “no” and the result is that the dog doesn’t get something greatly desired without ever understanding why.

Worst of all, people often become angry and punitive toward their dogs along with the word “no,” damaging their dogs’ trust in them and in other humans. It’s no wonder that many trainers simply give up on the word and want to throw it out of the dog-training dictionary.

If you can keep solidly in mind that a dog is not a human, and use the word “No” in specific ways, there are at least three uses for this word. The first would be in an emergency. Because it is so natural for humans to blurt out the word “no!” it might be what comes out of your mouth at such times. A dog who has learned through gentle human handling that “no” simply means “stop” may be saved from an accident by this use of the word.

Another way you can use the word “no” is when your dog does a behavior you want the dog to stop. As often as possible, this use of the word “no” needs to be part of a phrase, such as “No licking.” You might say “no” to stop the dog from doing something and then give the dog a direction. There are other ways to say this, though, such as “Leave it.”

In either case, this use of the negative words would be DURING the action, in order to redirect the dog. If the dog has jumped up on the sofa and you want the dog off the sofa, “no” is not meaningful communication. Instead, say (and signal) “Off the sofa,” followed by praise when the dog does it.

If the dog is just about to jump up onto the sofa, it can be useful to say “No, come”—as you signal with your body language for the dog to come to you. Then you praise, and direct the dog to a resting place acceptable to you. When the dog settles in that place, you reward. This is how you teach a dog what TO do, rather than trying to teach a dog what NOT to do.

If you have an expression with your dog such as “Leave it,” “Off the cat,” or “Let her go” (when a dog is about to chase or grab another living creature), use the specific language instead of “no.” Teach your dog as many word cues as possible. But if something arises that you don’t have a cue for, the word “no” can be helpful for those dogs who have not been traumatized by it in the past.

Another use of the word “no” is a soft, drawn-out sound when working closely with your dog. It means, “That’s not quite what I have in mind—can you think of the right action?” If you have a word for that other action, you may want to tell the dog.

Or perhaps you are trying to help the dog make a choice you think the dog is ready to make, as a learning experience, without prompting from you. Your voice needs to be calm. The goal is to help the dog think rather than interfering with the process. Learning that happens in this way is special, building the dog’s confidence both in you and in his or her own ability. When the dog makes the right choice, then of course you’ll use joyful praise that creates a real training celebration moment.

Anger Impairs Judgment

Angry people are far from being at their best, especially in their ability to think clearly. This is why the trainers caution about the word “no.” The way we behave influences what we think and feel. Indulging ourselves in yelling and hitting with our dogs is poor communication and poor training. This kind of human behavior damages dogs. In a moment of self-indulgent anger, a person can create a problem in a dog that would take a lot of time and expert knowledge to rehabilitate. Other people may pay the price for that person’s thoughtless behavior.

If avoiding the word “no” as a general rule with your dog will cause you to stop and think about how you handle and talk to the dog, then that is a great rule to follow. The word “no” doesn’t have any special power with a dog. If it would contribute to a human in the household getting too harsh with the dog, it’s best to eliminate it from the dog-handling vocabulary. You don’t need it!

A Word is Just a Sound

A good alternative to the word “no” to have your dog stop is just about any sound you can make with your voice. It helps for it to be one syllable, and not to have any particular meaning to humans.

Because you don’t make the special sound in everyday speech, the dog doesn’t hear it and misunderstand, or learn to ignore it because of hearing it often when people talk. You’re likely to think before you use the special sound, because it doesn’t pop out as frequently as “mo.”

Whether you use the word “no” with your dog or not, teach a special sound as well. Make it mean—“Stop—look at me for instructions!” And always end it with something good, so the dog has strong motivation to look at you and never any fear of the special sound.

Dogs can learn many sounds, and can distinguish between similar sounds quite well. After all, there’s not much difference between “sit,” “stay,” “stand,” and many other words that thousands of dogs have learned. Dog hearing is extremely sophisticated, as is their ability to perceive body language. Communicating effectively with a dog can be thrilling. The more things you learn together, the deeper and more satisfying your relationship