Jake Gyllenhaal struggled to fake a British accent.
The American actor - who plays the role of Prince Dastan in new movie 'Prince of Persia: The Sands of Time' - admitted getting into shape might have been tough, but faking the British accent was even more demanding.
He told BANG Showbiz: "The accent definitely. It's daunting trying to do any kind of service as an American to such a beautiful, fluid speech pattern that you all have. We are just barbarians in comparison."
The 29-year-old heartthrob - who stars alongside Gemma Arterton in the action adventure movie - claimed it was only through the persistence of director Mike Newell that he managed to pull it off.
He said: "It did help being surrounded by an international crew, but a primarily British cast and somewhat British crew. So I would speak, as soon as I got out of the car, I would speak with the accent all day and journey from region to region around England as I spoke to different people.
"Sometimes I would sound like them in takes and the director Mike Newell would shout, 'Dear boy, that doesn't sound right, do it again!'. I would say the accent was the hardest part to manage."
Jake has previously spoken about how the role was such a challenge because he needed to be in perfect physical condition.
He said: "I never did anything this intensive before to change my body. It's a physical role. And when I commit to playing a part, it's 110 per cent."