Natalie Portman would feel "silly" if she tried to stay in character when not filming.

Natalie Portman

Natalie Portman

The 'Jackie' actress - who is pregnant with her and husband Benjamin Millepied's second child, a sibling for five-year-old son Aleph - has a lot of "respect" for method actors as she insists there is no way she would be able to immerse herself in a role so deeply, she insisted on carrying it on at home.

She said: "I respect people who are able to stay in character all the time but I can't do it. I feel really silly.

"I can't go back to my family and be [in Jackie Kennedy's voice], like, 'Hi everyone.!' [Aleph] would be like, 'Mum, stop.' "

Though the 35-year-old actress feels very lucky she rarely has to audition these days, she admits that can be restricting as she doesn't get the chance to prove herself in a different type of role.

Asked if she still has to audition, she told OK! magazine: "I am very, very lucky that I don't usually have to.

"But there's a downside to that too because people tend to think they know what I can or can't do.

"Choosing projects, I'm impulsive. A lot depends on the character, the script, the director...

"Nicole Kidman said something to me that stayed with me for so long. We worked together on 'Cold Mountain' when I was 21 and she said, 'You never know how a movie is going to turn out but you can ensure your process is interesting if you're working with an interesting director.' "

And these days Natalie also has to factor in the impact on her family when she's deciding whether to accept a project.

She explained: "Recently the extra layer is logistics because it takes a big toll on my family to be constantly moving around.

"They're like, 'Go to New Zealand for four months!' And I'm like, 'What planet are you living on? I have a kid in school!'"