The Simpsons, Sky1, 7.30pm.

NANCY CARTWRIGHT is the boy who never grew up.

The 52-year-old is preserved on screen as cartoon character Bart Simpson, who celebrates his family’s 20th anniversary this year yet remains a ten-year-old in his short blue trousers.

“I’m five times Bart’s age and I’m still ten, it’s crazy,”

laughs Cartwright.

While Bart is spiky-haired and sharp-tongued, Cartwright is warm and glamourous, but she credits Bart with keeping her young.

“It helps me keep youthful because my biggest fans are these little guys and if they see what I look like and I turn around and say, ‘Hi man, I’m Bart’, in the voice, they’re shocked. It’s awesome, I love it,” she says.

Cartwright cannot believe that what started out as short “bumpers” on The Tracey Ullman Show in the US is now a global phenomenon which boasts dozens of characters living in fictional town Springfield.

“Back then the family was not fleshed out. Bart was the antagonist of the group, Lisa was the sensibility, and the mom was doing the best she could with the dad mostly beating up on Bart.

“But when we went to the half hour we started getting the taste of the possibility that this could expand to way more than just what was on Tracey Ullman because we had half an hour now to make these characters real.

‘‘At the time, I wasn’t looking far into the future.

I was the lead because Bart was definitely positioned as the star of the show, which I thought was quite cool, but there was no concept of ten years, 20 years, it was just like ‘I hope we get picked up for another 13 after this’,” she says.

Not only has Bart’s character been fleshed out, but Cartwright thinks he seems more of a cheeky tyke than a real villain as times change.

‘‘Twenty years ago, Bart was perceived as worse than he is today and I’m glad Fox has kept a little more control on his behaviour, more than some of the other networks have done with their cartoon characters, even though we now get away with things we couldn’t have done back then,”

she says.

IT was Bart’s devil-may-care attitude which attracted Cartwright, who honed her voice talents by doing public speaking while at school, to the role.

She describes her audition. ‘‘They were looking for an eight-year-old child, who was a girl, the famous Lisa Simpson, but I saw the description of Lisa and her little monologue and next to that was a picture of Bart, and for Bart it said ‘ten-yearold school-hating underachiever and proud of it’. Now, between eight-year-old child and what I just said what would you rather do? So, I read for the part and that was it, they hired me on the spot.”

That casting has led to a 20-year working relationship with the show’s creator, Matt Groening, its executive producers and show stalwarts Dan Castellaneta (the voice of Homer), Julie Kavner (Marge) and Yeardley Smith (Lisa).

The Simpsons is now broadcast all over the world and is the longest-running comedy in television history.

Cartwright admits that the job’s a good’un. Describing her typical day, she says: “It’s kind of done like old radio in a way, where we’re all in a big sound stage, we each have our own music stand in front of us with our script. We do four takes and we’re in at 10am and we’re out by about two in the afternoon. It’s not bad.”

Part of the appeal of the show is its treatment of major topics in a style which talks to and amuses children and adults.

Cartwright has one thing she’d like to see happen to Bart, and it’s a wish made by a 52-year-old woman rather than a tenyear- old boy. ‘‘I’d like Bart to meet Hugh Jackman. I don’t know if Bart would necessary want to meet him but Nancy Cartwright would,” she says.