Language Can Express Without Defining a Person
We learn a great deal about someone through what they say and how they say it. A promise shows a commitment. A question shows where their attention has gone. A conversation can let us meet an aspect of a person we had not seen before.
That does not make language a complete definition of them. Any description selects and leaves things out. Even a person's own account can change as they notice more, live differently, or find better words.
The limit does not make speech useless. We can use it to express, ask, correct, and make ourselves known without demanding that a sentence contain an entire life. A plain statement may sometimes carry more than an elaborate explanation.
Words matter because they take part in a relationship, not because they can finally settle who either person is. We can listen closely while leaving the person larger than the description.