my friend had a brain bleed stroke the doctors said he has15% brain damage its that a lot

Hello Anon

Thank you for writing.

15% brain damage is just that - 15%. Obviously the kind of damage done has affected his speech and right side. He should be taking part in a rigorous treatment plan including various therapies (speech/physical/occupational).
To get a prognosis, he will need to continue treatment and wait for evaluations. His doctor and therapy team can help further with questions.
Best,
Susan