It is more factual and accurate to evaluate and admire an animal's intelligence by looking at its own innate biological abilities than by how much human language it can learn. In fact, the way humans and animals can bond and connect without language makes it all the more remarkable.
Why Is it Inaccurate to Say That Animals Have their Own “Languages”? The Remarkable Features and Versatility of All Human Languages
We now know how limited animal communication is in what it can express. In contrast, one of the hallmarks that makes human language unique is its capacity for creativity and lack of limitations on what it is capable of expressing. (2) For example, people can talk about true things, or we can lie about things; we can discuss abstract concepts like beauty, war, or kindness. We can give each other directions for travel or instructions for how to bake a cake! Another ability we take for granted is being able to discuss stuff that does not exist in the present moment, or, that is not in our purview at the time of the utterance, or even something that will never happen, or could never be. Some linguists call this ability displacement, and note that it has never been observed in animal communication. (5)
People can lie and discuss abstract concepts.
Negation is another feature that is both exclusive to and present in every single human language—including those found in indigenous cultures without advanced technology. Animals are not able to express negation. (3) While some may say that their dog can “let them know” that it does “not” want to eat something by turning away from it, this is not the same as expressing negation grammatically (linguistically). For example, you could close your eyes, or be on the phone, and hear someone utter the words “I do not want to eat these anchovies on my pizza.” Even without context, visual information, knowing the person, or even seeing the person or the anchovies, you would comprehend this negative utterance perfectly, as long as you are a speaker of the language in which it is spoken. This is another distinguishing feature between human language and animal communication. We can easily combine displacement with negation to illustrate this: Imagine a dog explaining that it doesn’t mind that you are out of a certain doggie treat, because it liked that treat last year, but doesn’t like that treat so much anymore.
The number of words in human languages can vary, but human languages have hundreds of thousands of words. (2) Research on the jumping spider, on the other hand, finds 24 total signals that the male spider produces in order to entice the female spider to mate. (4) Other research finds 11 basic vocal sound types in wolves, and as few as 4 in some dog breeds. (1) Even if one were to argue that the basic sound types of the dogs and wolves could be akin to human language phones (those are discrete sounds, like consonants and vowels), instead of words, we know that the bark types aren’t combined to form meaningful units, the way sounds combine to form words, but rather are repeated over and over, one bark type at a time.