Father Knows Best?

Ever since he made a surprising success of “The Wedding Singer� last year, the media has been beside itself about the presence of not one but two Adam Sandlers: the sweet-natured, gentle romantic of that film and the more, shall we say, juvenile comic of “Happy Gilmore,� “Billy Madison� and “The Waterboy.�

“Big Daddy,� Sandler’s latest film, reconfirms the existence of those two Adams. It also shows that, commercial considerations aside, inviting them to share a film is a miscalculation, the equivalent of asking Jerry Springer and Charlie Rose to co-chair the same charity ball.

“Big Daddy� started life as a script by Steve Franks about a single guy who suddenly has to cope with a child in his life. When that notion was transmogrified into a vehicle for a major star, the comic and his writing partner Tim Herlihy completely Sandlerized the premise to the point where many of the things that take place on screen make sense for Sandler’s super-popular persona but not for the film.

Sandler plays 32-year-old Sonny Koufax, once a promising lawyer but now a prototypal Manhattan slacker and a drag on everyone’s reality who has a job taking tolls at a bridge but really lives off a settlement he got as the result of a minor traffic accident.

Sonny’s girlfriend Vanessa (Kristy Swanson), who’s put up with him for quite awhile, is getting tired of our hero’s aimless life. She precipitates a crisis by leaving the city for a few days and letting Sonny know that she’s seriously considering leaving him as well.

Even before a sad-eyed child appears on Sonny’s doorstep, there is a major disconnect between what the film, directed by “Happy Gilmore’s� Dennis Dugan, tells us this man is like and the evidence of our own eyes.

Yes, “Big Daddy� admits, Sonny may be a bit irresponsible, but he’s really just a fun-loving big kid, someone who’s never ever too busy to stop and smell the beer while his careerist friends plunge ahead in a search for worldly success.

The Sonny we see, however, is nothing of the kind. He’s whiny, obnoxious and insulting in both passive-aggressive and old-fashioned aggressive ways. Nothing pleases Sonny more, for instance, than the mean-spirited teasing he rains on Corinne (Leslie Mann), the fiancee of his roommate and best friend Kevin (Jon Stewart). Now a doctor, Corinne once worked as a waitress at Hooters, and Sonny would sooner die than miss an opportunity to relentlessly taunt her about her anatomy. All in good fun, you understand, all in good fun.

While Kevin’s away on business, that small child with the most woebegone face in the Empire State is delivered to the apartment. This is 5-year-old Julian (played by twins Cole and Dylan Sprouse), sent to live with Kevin, the father who doesn’t even know he exists.

Having no choice but to look after the boy until his roommate returns, Sonny doesn’t know what to do with Julian except treat him as an equal. That means turning the lad into a kind of Austin Powers-ish Mini-Me, a junior version of Sonny’s antisocial persona.

So off the two of them go to Central Park, where Sonny teaches Julian to trip in-line skaters because they look funny when they fall down. Sonny also teaches Julian to urinate on the walls of snooty restaurants (an image that’s been plastered across America) and when the youngster wets his bed, Sonny just puts some newspapers over the damp sheets. Who knew child-raising could be so simple and so much fun?

At some point in all of this, Sonny gets the crack-brained idea of pretending to be Julian’s father so he can adopt the tyke and make a favorable impression on Vanessa. Sonny’s censorious father (Joe Bologna) thinks the boy would be “better off living in a dumpster,� and it’s an open question whether he’s right or not.

It is the iffy premise of “Big Daddy� that this experience with care-giving suddenly and miraculously turns Sonny into a better human being. This is dubious even in theory, and in practice Sonny’s conversion is more simplistic and pro forma than it sounds. “Big Daddy� is so bound and determined to have a sensitive Sandler it doesn’t notice that the changeover couldn’t be less believable.

The same goes for the love affair that improbably flourishes between Sonny and Corinne’s attorney sister Layla, played by “Chasing Amy’s� Joey Lauren Adams like even she can’t believe what she’s getting into. No, no, no, you want to yell at the screen, no way this is the man of your dreams.

Sandler, if press reports are to be believed, all but micromanages his films, worrying over them to the smallest degree. A good thing, but in this case it led to a not-seeing-the-forest-for-the-trees scenario that contributes to “Big Daddy’s� problems.

For if this film’s underdeveloped script and dubious premise are to work, you have to unconditionally love the actor no matter what he’s doing. You have to take his good humor, his miraculous conversion, everything good about him, completely on faith, just because he’s Adam and you love him. There’s no doubt Sandler is talented, but if he persists in believing that, like Elvis, his presence alone covers a multitude of omissions and inconsistencies, he will squander his gift and make a series of forgettable films in the process.

* MPAA rating: PG-13, for language and some crude humor. Times guidelines: Bodily functions and a young child taught to curse and misbehave are played for laughs.

‘Big Daddy’

Adam Sandler: Sonny

Joey Lauren Adams: Layla

Jon Stewart: Kevin

Cole and Dylan Sprouse: Julian

Josh Mostel: Mr. Brooks

Leslie Mann: Corinne

Joe Bologna: Mr. Koufax

An Out of the Blue Entertainment/Jack Giarraputo production, released by Columbia Pictures. Director Dennis Dugan. Producers Sid Ganis, Jack Giarraputo. Executive producers Adam Sandler, Robert Simonds, Joseph M. Caracciolo. Screenplay Steve Franks and Tim Herlihy & Adam Sandler. Story by Steve Franks. Cinematographer Theo Van de Sande. Editor Jeff Gourson. Costumes Ellen Lutter. Music Teddy Castellucci. Production design Perry Andelin Blake. Art director Rick Butler. Set decorator Leslie Bloom. Running time: 1 hour, 35 minutes.

In general release.