I looked up the symptoms of aphasia. They sure sound like what tfg is exhibiting

[Siwsan]

I had an uncle who suffered from aphasia. He went in to full blown dementia.

From the Mayo Clinic:

A person with aphasia may:

Speak in short or incomplete sentences
Speak in sentences that don't make sense
Substitute one word for another or one sound for another
Speak unrecognizable words
Have difficulty finding words
Not understand other people's conversation
Not understand what they read
Write sentences that don't make sense

Causes
Brain damage caused by a severe head injury, a tumor, an infection or a degenerative process also can cause aphasia. In these cases, the aphasia usually occurs with other types of cognitive problems, such as memory problems or confusion.

Primary progressive aphasia is the term used for language difficulty that develops gradually. This is due to the gradual degeneration of brain cells located in the language networks. Sometimes this type of aphasia will progress to a more generalized dementia.

https://www.mayoclinic.org/diseases-conditions/aphasia/symptoms-causes/syc-20369518