By Adrienne LaFrance

Before you say “I told you so,” let me explain. I wasn’t expecting Annie Hall. I thought Because I Said So might be likable in a Something’s Gotta Give kind of way. I was wrong.

Diane Keaton’s latest star vehicle is an empty vessel of a romantic comedy, pieced together by poorly scripted slapstick, boring dialogue, and too many genre clichés.

Here’s the story: High-strung single mother of three grown daughters Daphne Wilder (Diane Keaton) wants to ensure that her youngest, Milly (Mandy Moore), isn’t doomed to spinsterdom. The meddling mom secretly places a personal ad for her daughter, hoping to select Milly’s Mr. Right and trick her into thinking she finds him herself.

The script leaves the actors little to work with. Keaton’s character is an unconvincing combination of aggression and innocence. Moore shows that she has some emotional range but is given little of substance to say or do. Lauren Graham (who proved her knack for comedic timing in the hit teen drama Gilmore Girls) is pretty well stifled in the role of the most grounded Wilder sister, a psychologist bothered by an attention-craving patient. The third Wilder sister, played by Piper Perabo, has only a handful of lines and barely appears in the film (except to scold her mother’s overbearing nature and to divulge embarrassing details about her sex life).

The dialogue is mostly made up of generic mother-daughter arguments (“Stay out of my personal life,” “But I know what’s best!”) and concessions (“I just love you so much, daughter.” “Oh, mom, me too.”) with awkward mother-daughter sex talk interspersed throughout. On one shoe-shopping excursion, the Wilder daughters talk explicitly with their mother about the intimate details of relationships with their husbands and boyfriends– helpful sound effects included, of course.

But the scenes with sound are a relative blessing, given how low physical comedy takes the film. In at least three scenes, Keaton trips and flails before clumsily dropping a large, elaborately-decorated cake. Her daughters are often juggling armloads of things, too. None of it works.

The rest of the film is a series of weak genre clichés:

• A romantically-impaired character checks her answering machines, only to hear “you have no new messages” (doesn’t everyone have voicemail now anyway?).

• A pair of Asian beauticians talk about the main characters as they massage them. Thanks to subtitles we’re in on all the crude laugh lines. Lucky us.

• Of course, the grand-finale romantic speech given in front of a group of strangers who are moved to applause by the hackneyed gesture.

Finally, costumers have Keaton dressed in a strange bandana-like scarf in one scene and a jacket and bow tie in another. She could pull off that kind of fashion quirkiness in 1977, but now it is contrived.

My advice: Go watch the trailer on the official site. It will give you that romantic comedy warm fuzziness without having to sit through the actual film. Why? Because I said so, that’s why.