When her manager called to tell her the news, 'at first I thought it was a joke', she says. After reading an e-mail confirming it, she called longtime boyfriend Paul Wong Koon-chung, the former member of the band Beyond, and finally burst into tears.

'I'm very happy,' says Chu, wearing a cream blouse and short-sleeved black jacket over black trousers and boots. 'Because of my looks, I must work harder than others to show that I'm not just a pretty girl.' It was her first major nomination since she was shortlisted for a Golden Horse Award in 1999 for playing a junkie in The Boss Up There. It seems challenging roles bring out the best in Chu. When she heard about the Golden Horse nomination she was recording a TV series on the mainland and cried tears of joy.

'This time,' she says, beaming an almost ever-present smile, 'it's even more emotional. It was totally unexpected. For me this is something that's really far away. I mean, I watch CSI, Criminal Minds and many foreign TV series. There are so many actors and actresses that I admire who will be there. It's like a dream for me.'

She's in good company in the category she's nominated too. The others hoping to pick up the statuette at the ceremony in New York on November 28 are British veteran Julie Walters, Brazilian actress Adriana Esteves and Sweden's Noomi Rapace.

Chu hasn't decided what to wear at the awards show but says that she'll probably choose something traditionally Chinese.

In the meantime, Chu is having a busy time. Her first stage play in a decade opened at the Ngau Chi Wan Civic Centre on Friday; it runs until November 13. Based on The Goodbye Girl, the 1977 Hollywood comedy romance movie, she takes the role played by Marsha Mason in the film, as a jobless dancer who, after being dumped by her boyfriend, has to take in a struggling off-Broadway actor to support herself and her daughter. They start off arguing but there's a growing appeal between the two. Her leading man is Chan Suk-yi.

When we meet Chu is in the throes of rehearsals but she sizzles with energy. Chu is demonstrative when she talks, frequently gesticulating with her fingers, long and slender like a pianist's. She hasn't done dramatic theatre for the past 10 years, so she's looking forward to getting back to treading the boards.

'Acting was my major,' says Chu, who graduated from Hong Kong's Academy for Performing Arts in 1992. 'I love the stage. The first time I saw the Broadway show The Phantom of the Opera my hair stood up on end. It's so powerful: the music, the voices. The whole spectacle is awesome.'

Born in Kowloon and raised in the New Territories, her father was a maths teacher, before he set up a plastic bag manufacturing company with her mother. His only condition to her taking a course at the APA was that she promised to finish it.

Chu originally wanted to be a scriptwriter and applied for that course. 'I love stories,' she says. Instead, the academy offered her a stage course.

Afterwards she took stage roles, presented children's shows on TVB and did modelling, before moving into film, earning recognition in roles with comedian Stephen Chow Sing-chi. Since then she's become a household name in Hong Kong, Taiwan and the mainland for her television roles.

'I love watching films and television. Really I'm watching people's emotions,' she says, after a photo session in which she puts on fake lashes and gives the kind of seductive smile that's made her a pin-up.

'Now, when I watch a film I mostly like to watch the actress and how she plays different roles,' she says, citing the film Monster, starring Charlize Theron. 'She is such a gorgeous actress but she had to play a monster, so I love this film.'

Chu admires the versatility of actresses such as Amy Adams and Meryl Streep, because their talent means they can extend their careers longer than many of their peers. Growing up, her only idol when she was a child was actress Carol Cheng Yue-ling, one of the city's biggest stars in those days.

'I like different challenges because when I look down the well, I still can't see the bottom. I hope there's no limit for my acting,' she says of her career. 'That's why I love to watch Meryl Streep after so many years. She can express so many small details on her face. She's like a teacher to me. When I watch her I learn from her. Watching her movies is like doing my homework.'

She also praises Marion Cotillard for her performance as the enigmatic French chanteuse Edith Piaf in the Oscar-winning 2007 biopic La Vie en Rose. 'She's very pretty but her acting is incredible,' says Chu, who acknowledges that an Emmy nomination may open the door to new opportunities overseas, which she says she would relish.

When Chu is offered a role, she first decides if the story is compelling enough and then looks at the strength of the female role. Even so she can't be too choosy, she says, because she doesn't have a big company behind her. While fans may remember her more for sexy and comic roles in films such as Raped by Angel 2, she doesn't have any regrets about roles she has taken in the past.

Still, she's frequently disappointed when a script is good but the filming doesn't live up to it. Sometimes on the mainland, directors are ambitious but their abilities have limits. 'It makes me depressed and maybe I can't perform to my standard.'

She had no such qualms about the film that led to her Emmy nomination. When cast in A Wall-less World, she told the director that she needed to do research and preparation.

Chu proceeded to visit hospitals, rehabilitation centres and the homes of wheelchair-bound people to learn all that she could. It was an eye-opening experience for her as a person as much as an actress.

'I found out that a lot of people who are paralysed are only in their 20s,' she says.

'It's really important to start recovery in the first three months. At that time, it's very difficult for them to do anything an able-bodied person can. They can't even use their hand to pick up a glass of water or comb their hair. So they have to adjust to learn a new life, just like a baby right from the start.

'It's painful and there is mental anguish. The main point is they have to tell themselves they're not totally useless,' she says.

And that's what her character does. The disabled people she met were eager to help her, she says. 'They were very happy because finally someone would do something to tell the world exactly what it is like for them.' Some were invited on to the movie set.

In the film, Chu used a manual wheelchair rather than an electric one and discovered how hard that was on the hands. When she went out with one of the disabled women she had met, using a wheelchair, she found out at first-hand how people reacted.

'It was a very hard feeling,' the actress recalls. 'When I meet anyone in a wheelchair now I make sure that I give them 100 per cent focus to show them respect.'