As the title suggests, “Spanglish” is about the mingling of two cultures: specifically, a family of privileged white Brentwoodites and another of poor, plucky Mexican migrants.

Writer/director James L. Brooks (“As Good As It Gets") also uses the title to symbolically express the collapse of a marriage: two people incapable of speaking the same language.

You must admit, it's a fine title. Versatile. Descriptive. If only the movie itself — and its serio-comic depiction of cultural and domestic collision — could provide the same kind of all-wheel traction.

Blessed with a very decent ensemble cast — some ads are billing the film as an Adam Sandler vehicle, but don't you believe it — and flashes of Brooks' sparking verbal genius, “Spanglish” is still a halting entertainment, amusing but strident, with a certain sentimental bias that comes out in coughs and fits.

For instance, it's not very funny when rich, shrill, decathlete-fit housewife Deborah Clasky (Tea Leoni from “Bad Boys”) sits down to interview her new, non-English-speaking maid, Flor (Spanish bombshell Paz Vega), and receives a minute-long lesson on how to roll her Rs. Ho-ho, good one.

Trust me: by now, everybody in Southern California — no matter how high up in the glass tower — knows how to roll their Rs.

Later, when Deborah's celebrity-chef husband, John — played by a serene, shlumpy and wholly non-irritating Sandler — gets a glowing write-up from a prominent food critic, she throws him onto the bed and makes brief, unculminated love to him, then crumples into a heap and bawls her eyes out.

Only Brooks knows for certain what he was trying to communicate with this scene. Is Deborah unsatisfied, frigid or just stark-raving mad? Suffice to say, the woman never really comes across as a credible human being. If anything, she's like a souped-up clone of Annette Bening's bitter spouse in “America Beauty,” down to her affair with a smarmy real estate agent (Thomas Haden Church from “Sideways”). Brooks uses Deborah like he used Deborah Winger's cancer in “Terms of Endearment” — as a dramatic twizzle-stick. Seeing evidence of Deborah's superficial, neuroses- spawning parenting style — she buys a new outfit for her chubby teenage daughter (newcomer Sarah Steele) that's several sizes too small, hoping to shame the girl's weight off — Flor becomes increasingly protective of her own daughter (Shelbie Bruce), whom she fears is being molded into a snob by her employer.

Likewise, Deborah's emotional remoteness gives John an alibi to develop special feelings for Flor, which is sort of a cliché, no? The house master hooking up with the help — it's like some hoary Monticello slave-fantasy, remastered to play in the 21st century.

Still-spry comedienne Cloris Leachman (“The Mary Tyler Moore”) is a total gas as Deborah's functioning alcoholic mother, a twittery old songbird whom Brooks favors with the movie's best lines.

"Lately, your low self-esteem is just good common sense," she happily chides Deborah when the daughter's marriage appears poised to go down the drain.

As a piece of social criticism, “Spanglish” wanders into some seriously disingenuous territory. Flor and her daughter, Cristina, aren't just characters — they're the new America, the face of the migrant community at large. And what does that face look like? A smokin’ hot size 4 who doesn't appear Latino (or sound it — Vega's accent is clearly Spanish) and a brilliant little girl who will one day wow the admissions board at Princeton.

Clearly, Brooks is attempting to hold a mirror in front of society, but in doing so, reveals himself as something of an aesthetic hypocrite: The narrator hounds Deborah and white women in general for their body obsessions, but conveniently lets slinky Flor off the hook.

“Spanglish” might abuse some characters and neglect others (the Clasky's son is a curious non-entity), but it always maintains wit, observance and focus. To this end, it's Flor and Cristina who ultimately pull “Spanglish” out of its tailspin.

While fireworks explode in the Clasky household, a more subtle drama unfolds between mother and daughter — a look of distaste that Cristina can't hide when she first sees Flor picking up the Clasky's garbage; Flor's obvious anxiety when Deborah tries to spoil her.

Meanwhile, something simple and profound evolves, almost out of sight, in the barrio of the human heart.