What is the Nature of Language?
If you are going to visit a foreign country, you may take a class in the language to prepare yourself. You will have to learn new words, as well as memorize the order in which those words are spoken.
The only advanced body language people use is in the case of sign language.
Horses do make some noises, but everyone knows that they use body language the most.
What once was thought of as mostly just "horses being horses," has turned out to be a very precise system of nuances, gestures, postures and intensity levels that are part of an over-arching ability of horses to
talk to each other.