Colin Firth couldn't stop himself stammering for two months after filming 'The King's Speech'.
The British actor had to affect a speech impediment for his role as King George VI in his latest film, and said afterward it took him some time to then lose it again.
Speaking at the Dubai International Film Festival, Colin said: "I'd say it lasted for a month or two, as far as I was aware of it.
"It still comes back every so often, but that's mainly me bumbling.
"The way you learn a musical instrument, the way you learn a sport is through programming, through repetition and if you spend two months interfering with your speech patterns, it's going to hang around for a while."
Colin, 50, also told how stammering became infectious on the set, and soon spread to the rest of the cast and crew.
He added: "We all got it, on set. Extraordinarily contagious! It was quite comical hearing Tom Hooper, the director, coming on set saying, 'Yes - I-I-I- could you - ah' and suddenly nobody could be understood, it was a very strange atmosphere!"
'The King's Speech' -which also stars Helena Bonham Carter and Derek Jacobi - will be released in the UK on January 7 and across Europe throughout February.