How many words can dogs really recognize?

Despite us living with dogs for more than 10,000 years, it’s only been in the last 20 that we’ve begun to get a sense for their real language-learning potential.

If you’ve ever had to spell P-A-R-K or W-A-L-K out loud to avoid the inevitable perk of your dog’s ears, you know they understand at least a few words.

Most dogs on average can learn over 150 words, which often includes names, places, actions, and toys (Campion, 2018). While that doesn’t seem like a whole lot compared to the three-year-old toddler average of 1,000—it’s certainly enough of a repertoire for them to have the ability to understand the difference between “going to grandma’s” and “going to the vet” (Law et al., 2017).

So who is Chaser and why did she stand out?

Chaser was what many consider to be an extraordinary example of how extensive a canine’s vocabulary can be. She was a border collie who demonstrated that she’d learned the proper-noun names of as many as 1,022 unique objects. Eventually, even her owner Dr. Pilley had to use a list to keep track of all the different toys and their names.


Chaser was what many consider to be an extraordinary example of how extensive a canine’s vocabulary can be.

Chaser the Border Collie, "The Smartest Dog in the World"

Over a three-year intensive training period with Dr. Pilley, Chaser showed in four studies that she could understand that names refer to objects, apply common-noun categories, and even infer the names of new objects by using the process of exclusion (Pilley & Reid, 2011). For example, if you presented her with a new toy among a group of known toys and asked her to bring it to you, Chaser would be able to map the newly spoken name to that of the novel toy. In this scenario, mapping meant that Chaser was able to identify which toys she already knew and recognized. By eliminating the rest, she could select the remaining object, which she "mapped" to its new name.

Despite us living with dogs for more than 10,000 years, it’s only been in the last 20 that we’ve begun to get a sense for their real language-learning potential. Now that there are tens of thousands of people teaching their dogs to express themselves with buttons, how much will we discover about dogs’ linguistic capacity over the next 20 years? 


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1 Campion, T. (2018). Dog Behavior: Modern Science and Our Canine Companions. Academic Press, 76.

2 Law, F., Mahr, T., Schneeberg, A., & Edwards, J. (2017). Vocabulary size and auditory word recognition in preschool children. Applied Psycholinguistics, 38(1), 89–125.

3 Pilley, J., & Reid, A. (2011). Border collie comprehends object names as verbal referents. Behavioural Processes, 86(2), 184–195.


  • Chrys

    Mataya one year (May 3, 2022) old Golden-Mountain-Doodle uses more than 30 buttons now.
    I feel like Mataya is in her teenage time though. She is more interested in talking with the other dogs and her friends than with me.

    She absolutely understand so much of what I say.

    We are at a cross section where I know she needs more words, but I am not clear on the direction to begin adding buttons yet.

    I want to scaffold her knowledge base efficiently. I do not want to just overwhelm her with a million buttons with no connections from one button to the next. It’s challenging to design the knowledge platform in concert with Mataya’s inquisitiveness. In tandem with her readiness to learn.

    I really wish there was a step-by-step guide to the progression of her language development.

    Being a teacher I feel as though I am more equipped than many other people for this journey, and yet I still flounder upon occasion.

    I miss teachable moments, and sometimes I’m just succumb to simply just being with Mataya in the moment… with nothing to be said.

    This process of language acquisition for Mataya requires time, patience, and definitely a compatibility between the dog and their guardian.

    And with all of that… I am learning as much as Mataya every day.

    Language is important. It certainly is a key to developing the relationship. But for a young teenage pup like Mataya, she’s made it clear that she lives for playing, and swimming, and participating in the joy of life.

    She asks to go for walkies four times a day at least. She is a celebration of light at the mention of going to visit one of her friends and to go swimming.

    It is a balancing act though in terms of deciding when to add more buttons.

    Mataya’s definitely more play oriented than becoming a book learned girl.

    She’s clearly considerate. She like to name the activity we are doing, and LOVES to know the plans of the future.

    I want to add buttons so she can see the words that she’s specifically searching for. It’s hard to anticipate those words though.

    She absolutely loves to listen to me tell her the parts of her body when I am blow drying her after she’s been swimming.

    As the blow dryer massages her arms and her feet I tell her, “shoulder”, “arm”, “paw”

    She listens intensely and I know she’s learning each and every part of her body.

    Nouns are easy, and fascinate her, but HOW to encourage her to use them, repeat them back to me so I can verify comprehension?

    I just have not figured out how to have her talk to me to name the parts of her body back to me yet. It Has to be a game. I just don’t know the game yet.

    I still am also struggling with the concept of time.

    She understands “soon”
    And “all done”

    I would like to be able to use the word “later”

    Instead right now I will say ‘first we will do this,’ ‘soon we will do that’, ‘now we are doing the other ‘…
    In order to tell her the activities of the day ahead.

    Mataya demonstrates that she fully understands the order of the activities of the day from my description.

    Everything now is up to me to learn how to expand her knowledge base if description. She understands but lacks the words.

    We could go faster maybe, but I’m not wanting to overwhelm her.

    It’s been a while since I’ve written a progress update. This kind of catches us up a little bit.

    I think I haven’t been writing so much simply because I haven’t been focused on videotaping Mataya with the buttons.

    Will try to do more of that soon.

  • Linda

    At the end of her lifetime, I believe it was estimated that Chaser knew almost 1,500 words – not just the identities of all her toys – but words used in conversations as well as commands. An excellent book is available on Chaser and Dr. Pilley is available in both paperback and Kindle: I highly recommend it for ideas on training and teaching your dog – or cat – how to learn a ‘human language’. Unfortunately, both Chaser and Dr. Pilley have gone across their ‘Rainbow Bridge’ – but we’re hopeful that others have continued this fascinating study in such a readable fashion, rather than scientific papers.

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