How many words do dogs really understand?

Admit it: You wish you could talk to your dog. It's man's best friend, so of course you'd like to be able to communicate with them better. You hope they understand more than the basics, like heel, sit, and stay. But does your dog really understand you? Do they grasp the concept of roll over?

Dogs can understand a lot of verbal cues, but how many depends on their breed and age. Some people have managed to teach their dogs more than 100 words, said How Stuff Works, with other dogs gaining vocabulary equivalent to a human toddler. A border collie named Rico showed an understanding of around 200 words. Researchers wanted to see how they could expand his vocabulary. They found that dogs like Rico can not only learn more words, but also exhibit some understanding of the process of elimination.

Scientists, explained The Bark, tested Rico's ability to learn new objects. They set out objects in different rooms. For the first test, Rico's owner asked him to fetch something familiar. The next test was for Rico to get something he didn't know yet amid a room of objects he does know. Rico brought back the unfamiliar item 70 percent of the time. The researchers repeated this test with another border collie, named Chaser, and a Yorkshire Terrier named Bailey. Both dogs were doing something called "fast-mapping," a process most toddlers use when they learn a new concept.

Can an old dog learn new words?

Learning the names of new objects is different from other concepts, like orders. According to EarthSky, the reason we know dogs can process human words is because they can follow some commands. Researchers also wanted to see if dogs respond to our words, or if they look for signs like tone, gestures, or emotions.

Researchers at Emory University scanned dogs to figure out their brain response to certain words. They took 12 dogs of different breeds and had their owner stand in front of an MRI. The owners said the name of a toy and lifted it so the dog could see it. Then they lifted the different objects, but said nonsense words. Scientists saw dogs' brains light up more with unfamiliar terms, suggesting they're focusing on these new words more because their owner wants them to learn it. While they can learn more vocabulary, their motivation to do so depends on praise from their owner. 

The Bark noted, however, that just because dogs can learn more than 100 words, it doesn't mean you can suddenly teach your old dog new tricks. It still depends on your willingness to train your dog. If your dog has already attached specific actions or words to things, it will be challenging for them to relearn new meanings. So no, you can't talk to your dog yet, but at least take comfort in the fact that, at some level, they do understand you.