as the object form of I 用作I 的宾格形式: They invited me to lunch. 他们邀请我吃午饭。
in spoken English as a one-word answer, or after the verb ‘to be’ 在英语口语中用作单个词的回答，或用在动词to be 后面: ‘Who did they blame?’ ‘Me, of course’ . “他们责怪谁？”“当然是我。” Jack didn’ t do it. It was me. 杰克没有做。是我做的。
used for referring to yourself when you are the person who is speaking or writing 我（说话或书写时自称）