Rita Tushingham says funny things as afterthoughts. “I always seem to be pregnant,” she comments, reviewing her tiny list of acting credits. “If I ever have children, they’ll probably be padded ones.” ...

The Knack . . . and how to get it, as film comedies go, is too clever for its own good. Based on Ann Jellicoe’s giddy, free-spirited play—still bouncing along off-Broadway—The Knack tells of a ...