“Dogs understand what some human words mean, according to a study published in the prestigious journal Science.
In a world-first experiment, academics in Hungary trained 13 dogs to voluntarily lie in an MRI scanner to monitor what happened in their brain when the researchers spoke to them.
They discovered that dogs’ brains process language in a similar way to humans, with the right side dealing with emotion and the left processing meaning.” https://www.independent.co.uk/news/science/dogs-can-understand-human-speech-scientists-say-a7216481.html
Real-life examples that involve animals and communication are full of areas where we are “rarely completely certain.”