Key for exercise Perfect tenses 1

1. Do you think Vicky's always known the truth about us? Correct.
2. That's been the second time you've forgotten to post something for me. Incorrect.
    Corrected: That is the second time you've forgotten to post something for me.
3. I haven't seen Peter since he begins seeing his new girlfriend. Incorrect.
    Corrected: I haven't seen Peter since he began seeing his new girlfriend. 
4. Ever since we met, you never asked me what I prefer to do. Incorrect.
    Corrected: Ever since we met, you have never asked me what I prefer to do. 
5. In all my life, I never spoke to someone who is quite so stupid. Incorrect.
    Corrected: In all my life, I have never spoken to someone who is quite so stupid. 
6. I don't think Paul and Carol have seen much of each other of late. Correct.
7. This is the only occasion that I've seen him wearing a tie. Correct.
8. Since he's lived here, he was usually extremely friendly. Incorrect.
    Corrected: Since he's lived here, he has been usually extremely friendly.
9. They'll join us after they'll get a bite to eat. Incorrect.
    Corrected: They'll join us after they have had a bite to eat. OR They'll join us after have got a bite to eat. 
10. He says he hasn't yet come to a final decision. Correct.