“As a boy, he’d taken classes at the Art Institute of Chicago, and in high school he’d painted and sculpted. He’d been a competitive swimmer and boxer in school, too, and as an adult was a fan of every televised sport, from professional golf to the NHL.”

想请问如何判断'd是等于had 还是 would？什么情况下等于had，什么情况下等于would。谢谢！