Gwyneth Paltrow didn't know if she'd be able to film when her father, actor and director Bruce Paltrow, died two weeks before Sylvia was due to start shooting.

"It was without question the worst and most devastating thing that has ever happened to me. I didn't know if I would be able to do the film," says the Oscar-winning actress.

"But my brother was really insistent that I do it. He said, 'you can't just wander around the house like a zombie, it's better that you have something to do when you get up every morning'."

Her state of mind helped her deal with her troubled character, real-life poet Sylvia Plath. Marriage to fellow poet Ted Hughes led to mental distress and her suicide at the age of 30.

"Considering how raw and just decimated I was as a person, combined with all my research about her, and when you are in that state and you read her poems, you are just there. It just required being her voice and her words," she explains.

Naturally enough, she listened to her poetry a lot. When Plath read her work, it was "very startling, very extreme" and Paltrow decided she wasn't going to try to copy the voice. "I just listened to a lot of the sounds and when I was reading out loud I would put colours of it in, but not to the extremes that she did."

The part was difficult to leave behind at the end of the day, and the actress remained in that state for a couple of months. She was probably difficult to be with around that time. "I'm sure I wasn't a lot of laughs by any stretch of the imagination because I was so depressed about my father, and then I was doing this incredibly heavy piece," she says.

Her own actress mother, Blythe Danner, plays Plath's mother in the film. That helped a lot, as they filmed together in New Zealand.

She feels various factors converged at the same time to make the poet kill herself. "I spoke to a friend of hers and Sylvia had spoken with her very candidly about her first suicide attempt. She said that the blackness and despair were so great that she had no choice," says Paltrow.

"Thankfully, she had come out of it, but if it ever returned, she would kill herself. She was very candid about it with this woman. Then she had this fantastic few years when she was very alive. She must have been manic depressive because people describe her as being in incredible ups and really horrible downs.

"But she had these years with Ted Hughes when they had this amazing kinetic thing together. It's amazing when you think about those two minds in one house, stalking, living, and loving.

"I'm not sure what catalysed the depression, whether it was his behaviour or if it was just chemical and it was coming back. But obviously the two things working together, finished her off."

Paltrow's own life has taken a new turn with marriage to British musician Chris Martin, from Coldplay, and pregnancy. "We're both very happy and excited," she says. "But I'm also a little superstitious about talking about it until the baby's born.

"When people say, 'are you going to find out the sex? Do you have any strange food cravings?', I don't want to answer those questions.

"But I'm very happy. I touch wood and I pinch my stomach. It's a good luck thing. I don't know where I got that. Now there's a lot more to pinch."

Filming Sylvia brought her to England, which she's come to regard as her second home. She's already displayed her flawless English accent in films such as Shakespeare In Love and Sliding Doors. The 31-year-old Californian star also has a Chelsea residence she owned before meeting Martin.

"When I first came over here to do Emma, I was so perplexed by the country, the culture, the people and I would never have considered myself an Anglophile," she says. "Then I completely fell in love with it."

Parenthood will mean she'll be working less. She feels she worked far too hard in her twenties.

"I did films back to back and made some weird choices. I realise I don't like being in the spotlight all the time, and after playing Sylvia, I realised I don't want to waste my time doing trivial things.

"Something happened when I turned 30. I can't fathom living the rest of my life without my father, but I have to. I've just got to adjust to my new reality. I have much less turmoil about who I am."

* Sylvia (15) opens in cinemas tomorrow.

Published: ??/??/2003