老师请说一些比较常用的在句子中区分过去时态和完成时态的关键词。

Question

老师，您好。

请您告诉我一些就是在单选中比较常见的区分过去式和完成时的关键词。

谢谢老师

Answer 1

完成时：
1) already: I have done my homework already.
2) since: I have been doing my homework since 2:00.
I have lived in London since 1970s.
3) now: I have got my ticket now!
4) so far: I have been doing well so far.
5) recently: I have been working hard recently.

过去时：
1) ago: I saw him two days ago.
2) 过去的一个时间点：如yesterday， last Monday, in 1977, in the 20th century: I watched a movie yesterday.
She was the most famous star in the 20th century.

注意：如果既有ago，又有since，那也是完成时，比如：
I have lived here since 10 years ago.