[fourtrees]

I'm not sure exactly what constitutes a 'severe language impairment'; there are lots of aphasias out there that only affect very specific parts of the whole language/writing system in the brain. They could be comprehend normally, but have trouble producing (on some level) speech or vice versa. If could comprehend spoken language without difficult, they could 'easily' complete tasks that didn't require those neural connections. Without knowing what the specific symptoms were, this is kind of a moot point.