(Cover) - EN Showbiz - Eva Green stayed in a different hotel to her Cracks castmates to ensure her character was believable.

The actress portrays Miss G in the movie, which was out in many countries in 2009 but is released in America today. The film is about the relationships between girls at a boarding school, where Miss G teaches and is a diving coach. The character becomes friendly with her students, leading to problems as the movie progresses.

Eva, 30, was terrified she wouldnt look like a real teacher in the film, as the female students were all in their late teens. She took drastic steps to ensure she would be able to command their attention.

I was worried about being believable as a teacher. The girls were nearly 18, I was worried about not having enough authority so I stayed in a different place, a different hotel, just to keep the mystery. The rehearsals really helped, we really got on. Theyre lovely girls, humble and a lot of fun, she said.

The most difficult scenes were the teaching scenes. I wanted to be strongly believable enough as a teacher which was difficult for me.

French actress Eva prepared for the role by perfecting her English accent, which she did by watching old movies. She also read the book by Sheila Kohler which the film is based on, and was amazed by the differences. Miss G is much tougher in the tome, but Eva wanted to play up other aspects of her personality.

I had to read it again and again and again because it is such a complex role and I was worried at the beginning because I didnt want her to look sadistic, I wanted to make her look at human as possible so I had to find her flaws and cracks, she told cinemablend in a video interview. Its a very damaged role and I had to do a lot of prep on it. (C) Cover Media