【正文】
I ___________ (not see) Justin since last Friday night. have not seen 2. We also use the present perfect tense to talk about something that started in the past, and is still happening now. 3. We use the present perfect tense when the exact time of an action is not clear or important. We use it with time expressions such as: already ever for just lately never recently since yet Exercise: plete the following sentences with the proper tense: (1) We ____________ (study) English for about five years. (2) They __________ (live) in the south since their daughter was born. (3) I __________ (read) your article three times. It’s well written. (4) The student ______________