'Failure to Launch' is Sarah Jessica Parker's second film since 'Sex and The City' (and her celebrated role as Carrie Bradshaw) came to an end. In last Christmas's comedy-drama 'The Family Stone', she played an uptight business woman meeting her prospective in-laws for the first time. Now she's starring alongside the ultra-sexy, laid-back heartthrob Matthew McConaughey. She plays Paula, who's hired by desperate parents with live-at-home sons - her job being to lure the sons into moving out of the family home. An odd concept, perhaps...

'Failure to launch' is an American phrase - what does it mean?
I guess it describes a growing phenomenon or a syndrome in our country where men are living at home long past what is considered an appropriate age. I was actually quite concerned about the title – I saw lots of critics just having a field day with it.

So why do you think a grown man would want to live with his parents?
I think there are real issues that are legitimate that keep a man at home - some of them are cultural and some of them are financial, and some them have to do with ailing parents or elderly parents. But in our movie this is just plain old simple convenience and laziness - and it provides for comedy.

Are you worried that your character Paula is quite heardhearted, luring men to fall in love with her, so that they move out of their parents' house?
She is. And it concerned me, but I also think she isn't without revelations. My basic feeling about her is that she must have been hurt pretty badly and deflected her own deficits in the romance department by being constructive about other people. But I hope she redeems herself in some way.

So, do you think women can really change men?
I would say that anybody who thinks they can really change another person, let alone a man, is slightly misguided. I have so many single women friends who date men who have big warning signs all over them. And they really feel that they are uniquely gifted or skilled in some way so that they will be the woman who finally fixes all these flaws.

What was it like working with Matthew McConaughey?
He and I had worked together before. He did 'Sex and the City' once, very kindly, and was pretty generous in spirit because he played a very vulgar movie star who happened to be called Matthew McConaughey! So I already held him in pretty high regard, and as different as we are (and as different as we work - he loves improvising and I'm pretty much a script person, just from being raised in the theatre) we somehow worked really easily together.

He's very athletic, and he's really, really skilled and I don't know how many crazy, dangerous things he's done – but, you know, he's a real outdoors person and I'm a real city person. I love concrete and I love architecture and the sounds of cabs and I'm very uncomfortable when it gets quiet, I find it unnerving and unsettling.

I don't think getting on with someone on-screen is anything you can plot or plan, because often when I've played opposite someone I have really liked, that just hasn't crossed the footlights or doesn't translate on screen. It's like trying to jam a puzzle piece together when it doesn't really fit or two pieces seem really flush. And that's the way it first felt with Matthew, physically on screen. But he's extremely comfortable in front of a camera - he really likes it, and this part suits him really well. We just didn't know what story we were telling at first.

Supposing you weren't married, would you go out with a man who lived with his mum?
It's very hard trying to imagine being single again. I would really not want to charter those waters anymore! If somebody were living at home and they were really funny and smart and interesting, and there was a pretty legitimate reason for them to be there, I would feel comfortable dating them. I don't know that I would feel comfortable going into the bedroom and closing the door. I think that might make me feel weird if the parents were, you know, present!

How do you think you'll feel when it's time for your son to move out?
At the age of three years old it's really hard for me to even imagine wanting him to leave the house, let alone forcing him out the door! But I hope that we are raising, in the end, an independent young man who feels confident that he can go into the world and who can always come home and always bring his laundry. He already knows that when he's married he's supposed to come home every Friday, no matter what his wife says, and have dinner with me. We've already decided his wife's name is Mary!

How did you know that your husband (Matthew Broderick) was Mr Right?
I'm not certain that one is really (especially at a tender age) certain of those things, but I definitely recognised a lot of qualities that I thought were wonderful and that I probably didn't even know that I was looking for until they were right in front of me. I think they were similar qualities to what my mother saw in my father, strangely enough. And, you know, we don't pretend to hold our marriage up as a standard, and I think we in fact decided to not ever suggest that it is a model by which everyone should judge theirs. Maybe that's why it's lasted.

Do you think you've managed to shake off the persona of 'Sex and the City's' Carrie Bradshaw?
I can't do much about the public's perception of me - I can only try to make the best choices given the opportunities that I have. But I'm very comfortable with the association of 'Sex and the City'. In fact, I feel very privileged to have had that really extraordinary experience and I also recognise the strong identification. And I don't feel it's defining me, because I've had so many interesting opportunities since the show ended. I feel I can both be really nostalgic about the experience, very comfortable about the association, and also get to be an actor and do different things. But it's been nice that both films ('The Family Stone', 'Failure to Launch') have found audiences and had some successes, either commercially or critically and I guess I'll know later on how definitive it was.