We use it to serialize ideas, and we have the ideas independent of language.
AI works on the serialization itself, which is very powerful because of the relationships between ideas are reflected on statistics in the serialization, but it lacks all the understanding, and can't create new ideas with reasonable resources.
I don't agree language is primarily about those things, but I want to point out this is a very human interpretation of language, that no LLM can perform.
“We refute (based on empirical evidence) claims that humans use linguistic representations to think.” Ev Fedorenko Language Lab MIT 2024