Aussie actress Isla Fisher

She was encouraged to try comedy by her fiancé Sacha Baron Cohen

By Kevin Maynard

"You'd work at the surf shop in a bikini, you'd go to school in a bikini," Isla Fisher says deadpan over drinks in Los Angeles. "And if you were murdered, you would be buried in a bikini." No, she's not reminiscing about her Australian adolescence, but about her stint as a scantily clad teen in a 1990s Down Under soap.

Those days are over for Fisher, thanks to her hilarious turn in 2005's "Wedding Crashers." She played a trust-fund, bipolar nymphomaniac who goes "Fatal Attraction" on her 6-foot-5 co-star Vince Vaughn. "There was just so much physical comedy to be mined when you're a tiny girl beating up a massive guy," says the adorably petite (5-foot-2) redhead, who, it turns out, is quite the firecracker.

She has a killer wit you don't see coming and, according to her "Hot Rod" co-star Andy Samberg, "a super sailor's mouth -- an Australian sailor's mouth." Some think it's sweet.

"Yeah! She's definitely not one to hold back on the [trash] talk," says Ryan Reynolds, who plays opposite Fisher in the Valentine's Day release "Definitely, Maybe." "She's sort of like a verbal surgeon with vulgarity. At the same time, she's a girl that could just as easily quote the most prolific authors of the world."

In "Definitely, Maybe," Fisher plays April, an apolitical freelancer who frustrates Reynolds' campaign fundraiser and then becomes his best buddy. "I think she starts out as a girl really frightened of true love," Fisher says, "and then grows into a more mature woman who's ready to be emotionally vulnerable. I loved the idea of doing a romantic comedy that wasn't formulaic and glossy. It felt like real people getting involved at different stages of their lives, and how important timing is."

In real life, Fisher, 32 on Sunday, is linked to Sacha Baron Cohen, the brilliantly demented British comic behind "Borat." The couple, engaged in 2004, had a baby girl, Olive, in October and divide their time between the United States and England. Fisher won't disclose details. "Oh, I don't talk about my personal life," she snaps. "I'm very good at that, sorry!"

What we do know is that Fisher (and, it's safe to say, Baron Cohen) is a huge fan of "Monty Python," the BBC's "Blackadder" and Christopher Guest movies. "I couldn't marry someone who doesn't have the same sense of humor as me," she says. "Humor's really important -- it's the most important quality in a person."

Still, it was Baron Cohen who urged Fisher to lighten up. "I was going up for a lot of dramas, and I wasn't having much luck," she says. "And Sacha was the one who said, 'You're crazy if you don't do comedy; you're one of the funniest girls I know!' "

All too aware that Hollywood is a boys' club, Fisher is busy developing her own projects, including an adaptation of the chick-lit bestseller "Confessions of a Shopaholic," in which she'll play the debt-ridden protagonist, and "Groupies" with "SNL"'s Amy Poehler, "about rocker chicks who are no strangers to the restraining order." Fisher says, "It's tough to be in comedy if you're a woman. You've got to develop your own material or you'll end up playing the girlfriend [forever]." I think we speak for the potty-mouthed actress when we say, #@&%*+$!