“服缓刑”常见的英文表达是 “serve a suspended sentence” 或 “be on probation”。
“serve a suspended sentence” 直接体现了“服（执行）缓刑”这一行为，强调正在经历缓刑这一刑罚执行阶段。例如：He was sentenced to two years in prison, suspended for three years, so he is now serving a suspended sentence.（他被判处两年监禁，缓刑三年，所以他现在正在服缓刑。 ）
“be on probation” 更侧重于描述处于缓刑考验期的状态 ，突出缓刑期间需遵守规定、接受监督的特点。例如：After he was found guilty of the crime, he was put on probation instead of going to prison immediately.（他被判有罪后，没有立即入狱，而是被处以缓刑。 ）