“犯愚蠢错误的人”可以翻译为 "a person who makes foolish mistakes" 或更简洁的 "a foolhardy person"（不过“foolhardy”更侧重于“莽撞、有勇无谋”，若仅强调“犯愚蠢错误”而非性格莽撞，前一种更贴切），最常用且贴合原意的是 "a person who commits silly mistakes" 。
He is a person who makes foolish mistakes due to his carelessness.（他因为粗心大意，总是犯愚蠢的错误。）
Don't be a person who commits silly mistakes; think twice before acting.（别做犯愚蠢错误的人，行动前要三思。）