forget to do sth.和forget doing sth.以及frighten 和frightened的区别?

问题描述:

forget to do sth.和forget doing sth.以及frighten 和frightened的区别?

forget to do sth.is 忘记去做某事
forget doing sth.is 忘记做过某事
frighten is 变得害怕 主动
frightened is 受惊吓的 被动