Language must be analyzed in terms of Receptive, Inner and Expressive Language Processes.
I am reminded of the case of Julia, a young woman in her late twenties, who was afflicted with a stroke which left her almost totally paralyzed from head to toe.
She could make a kind of a guttural sound, but no speech.
The doctors, nurses and family assumed she had no language, and hence everyone talked in front of her.
Frequently they referred to her as a vegetable, and made jokes or other unkind statements, assuming she could not understand.
In truth, Julia had considerable language capacity.
Only her expressive language was impaired. In terms of receptive and inner language, she was quite normal.
Hence, she understood and endured with anguish all that was being said.