I think my current best guess to this is something like:
When humans say thing X, they don't mean the literal translation of X, but rather are pointing to X', which is a specific symbol that other humans generally understand. For instance, "How are you" is a greeting, not typically a literal question. [How Are You] can be thought of as a symbol that's very different than the sum of it's parts.
That said, I find it quite interesting that the basics of human use of language seem to be relatively poorly understood; in the sense that I'd expect many people to disagree on what they think “There is a 20% probability that X will occur” means, even after using it with each other in a setting that assumes some amount of understanding.