Mr Morgan grew up in England and spoke only English for most of his life. But after his stroke last year he discovered he could only communicate in Welsh – even though he had never learned the language and had last visited the country 70 years before.
Doctors believe Mr Morgan’s experience is caused by a brain disorder called aphasia, which caused damage to the parts of the brain that governed his use of the English language.
With his faculty for English damaged, Mr Morgan’s brain appears to have fallen back on a language that he thought he never even knew – there are signs that Mr Morgan may have picked up some Welsh when he was young.
He lived with his Welsh-speaking grandmother as a child, and during World War Two he was sent with other children to Wales as an evacuee, to escape the German bombing of English cities.
“It gave my wife the shock of her life when I started speaking Welsh,” Mr Morgan told the BBC.