I can't imagine not knowing a language. I don't think that can even exist. Language is a way of expressing our thoughts and our emotions. It's a way of expressing ourselves. It is almost impossible to think of our thoughts without using a language. For example, even when I'm thinking, I'm thinking in the language of English. For some people who think without their language and in terms of perhaps numbers for math, it does not mean they don't have a language. They just think in different terms. Some people think in shapes and pictures, but that is also a language. If we were to say language is the way to express our thoughts, without language it will be difficult to have a thought. Without a type of language our minds do not have thoughts or a way of communication.