高一英语必修4 Unit 2 Grammar The usage of ing form(8)

E. 作状语的用法(在句子中表示时间、条件、伴随、结 果、原因等)

1.当主句中的谓语动词和-ing短语中动词所表示的动作同时发生 时，用-ing 形式, 否定式为not doingArriving home, she found the door locked.2. -ing 短语中动词所表示的动作发生在主句的谓语动词所表示的 动作之前， 用having done 形式(被动用having been done),

否定式为 not having (been) doneHaving failed the exam, he no longer played computer games. 3.-ing 形式作状语时，其逻辑主语通常为主句的主语

Not knowing what to do, your advice is important to me.4.从属连词+动词的-ing 形式\动词的过去分词 (when\while\once\although\unless, since, whenever, until, as if…) While reading the letter, she cried.