In conversation with Giles Paley-Phillips and comedian Jim Daly, John admitted he lost control of Sam’s stutter at point while filming a scene with Kit Harington.
He said: “Towards the end of Game Of Thrones, it became the only way I could act, and I got into the unconscious mindset that people want me to do this.
“I got into this trap with Sam, I set myself traps, because he had a traumatic childhood and suffered a lot – and it manifested through a stammer and a twitch sometimes.”
He added: “There are takes of me where it felt like it would be five minutes where I am just standing with other the actors and I couldn’t speak and I just can’t get the words out and certain sounds would trip me up.”
source: express.co.uk