直到上了当地的寄宿学校，我的表弟才意识到他在自理能力上的不足。(Not until)

Not until he went to the local boarding school did my cousin realize his lack of self-care abilities.

考查倒装句、时态、短语、和动词。原句前半段应译为时间状语从句，后半段为主句。主语 “我的表弟” 为my cousin；主句谓语 “意识到”，为realize；宾语 “自理能力上的不足”，应用短语lack of self-care abilities。从句中增补主语，用he；谓宾结构 “上了当地的寄宿学校” 应用短语go to the local boarding school。根据提示，Not until在句首，主句部分倒装，从句不倒装，全句使用过去时。故翻译为：“Not until he went to the local boarding school did my cousin realize his lack of self-care abilities.”。