P — Perfect, S — Simple / Indefinite
- When he entered [Past S.] the room, the movie already started [Past S.].
- He had worked [Past P.] for five years before he enrolled [Past S.] in the University.
- How many years had you lived [Past P.] in the center before he moved [Past S.]?
- By the end of the semester, students will have written [Future P.] two pieces of coursework.
- When we returned [Past S.] from the walk, the hostess cleaned up [Past S.] the dishes.
- I hope [Present S.] that by the end of the week the weather will have changed [Future P.] for the better.
- I accidentally met [Past S.] her in the street. We have not met [Present P.] since the childhood.
- After I finish [Present S.] reading the book, I will tell [Future S.] you the contents.
- When they came [Past S.], we discussed [Past S.] all the issues.
- They had conducted [Past P.] a series of negotiations before signing the agreement.