“一人演几个角色的”可以翻译为 “a person playing multiple roles” 或者 “an actor/actress taking on several roles”。
“a person playing multiple roles” 更侧重于描述行为本身，即一个人扮演多个角色这一情况。
“an actor/actress taking on several roles” 则更明确地指出是演员这一职业身份，在涉及表演、戏剧等具体语境中使用更为贴切。