Can a 1997 Chevy cavalier 2.4 twin cam fit in Buick skylark?

No, a 1997 Chevy Cavalier 2.4L Twin Cam engine will not directly fit into a Buick Skylark without significant modifications, if at all possible. While both cars are GM products from a similar era, the engine bays, mounts, and ancillary systems (like wiring harnesses and exhaust) are different enough to make it a highly impractical swap. You'd be looking at a massive undertaking involving custom fabrication and potentially significant engineering challenges.