It’s always nice to see an Oscar winner of a certain age like Marcia Gay Harden (“Pollock’’) make an increasingly rare big-screen appearance. Too bad this screwball romantic comedy from Canada turns out to be too much of a good thing.
Harden has a field day as a woman who accidentally ends up saving her husband’s mistress (Leonor Watling) — who has no idea who Harden is — from a suicide attempt.
The mistress is an actress, and accompanying her to an audition for support, Harden lands the lead in a stage production of “King Lear.’’ Eventually, she’s at the apex of a romantic rivalry between said husband (Joseph Kell) and a man she meets at a nursing home where her mother is dying.
“If I Were You’’ has more than its share of laughs, but director Joan Carr-Wiggin needed to cut half an hour to make this fly without interest flagging. She had the exact same problem with her last movie, “A Previous Engagement.’’