The ability to read, understand and communicate a language is definitely knowledge. And knowledge is power. Throughout history people have been swindled or taken advantage of because they couldn't understand the legal language used on a contract. A deaf person who is not taught a sign language of some sort will go through life unable to communcate, so language is definitely knowledge in that case.
To take this to the very beginning of time, primitive man discovered fire once upon a time. He learned that he could use this fire to cook his food and heat his home. This was knowledge. But that knowledge would have died with that man had he not developed a language to be able to describe this thing we now call "fire" and share it and its uses with his offspring and/or his neighbors.
Student or Learner