If you told me that everything I believe wasn't true, I would say prove it. No original person pointed up to the sky and said it was blue. The color of the sky is transparent. Our perception of a blue sky comes from the spectrum of light that makes it down to our eyes. Some nonhuman animals do have language, one obvious one would be dolphins, but even dogs and rodents communicate with each other, mostly nonverbal but language isn't just verbal skills. How do we know they aren't more advanced than humans linguistically? Well, I suppose we can't completely rule that out, but I would say the evidence doesn't support that. We can look at the brains of different animals and determine the size of their brains wouldn't allow for higher communication skills. Finally, how do we know what we see is really there? We don't, but we need to function within our senses, and if you concluded that things you see aren't real, you wouldn't live very long. I'm confident you would die if you were to walk in front of what appears to be a truck heading directly at you. Please don't attempt this.