掌握过去进行时的16个秘密信号词，轻松提升你的英语表达能力

1. be - 表示存在或状态，如“I was studying”（我正在学习）。

2. have - 表示拥有或经历，如“He had been working”（他一直在工作）。

3. do - 表示动作，如“She did her homework”（她做作业了）。

4. was doing - 表示过去正在进行的动作，如“He was reading”（他正在读书）。

5. has been doing - 表示过去持续到现在的动作，如“She has been running”（她一直跑步）。

6. has been doing something - 表示过去持续到现在并完成某事，如“They have been playing soccer”（他们一直在踢足球）。

7. had been doing something - 表示过去持续到现在并完成某事，如“We had been swimming”（我们一直在游泳）。

8. have been doing something for a while - 表示过去持续了一段时间的动作，如“She has been working on her project for two weeks”（她一直在忙于她的项目两周了）。

9. have been doing something for a while and now - 表示过去持续了一段时间的动作，现在仍在继续，如“He has been working on his report for three hours”（他已经在写报告三个小时了）。

10. have been doing something until now - 表示过去持续到现在的动作，直到现在仍在继续，如“She has been painting for an hour”（她一直在画画一个小时了）。

11. have been doing something until now and now - 表示过去持续到现在的动作，现在仍在继续，如“He has been playing the guitar for five minutes”（他一直在弹吉他五分钟了）。

12. have been doing something until now and now - 表示过去持续到现在的动作，现在仍在继续，如“She has been writing a letter for two days”（她一直在写信两天了）。

13. have been doing something until now and now - 表示过去持续到现在的动作，现在仍在继续，如“He has been playing basketball for an hour”（他一直在打篮球一个小时了）。

14. have been doing something until now and now - 表示过去持续到现在的动作，现在仍在继续，如“She has been cooking dinner for two hours”（她一直在做饭两个小时了）。

15. have been doing something until now and now - 表示过去持续到现在的动作，现在仍在继续，如“He has been cleaning the house for an hour”（他一直在打扫房子一个小时了）。

16. have been doing something until now and now - 表示过去持续到现在的动作，现在仍在继续，如“She has been gardening for two days”（她一直在园艺两天了）。

通过学习和掌握这些过去进行时的信号词，你可以更自然、更准确地表达过去某个时间点正在进行的动作或状态。记住，练习是提高的关键，所以多读、多说、多写，不断实践这些表达方式，你的英语表达能力就会得到显著提升。