Since vs. For w czasie Present Perfect

1. We haven't met forsince Christmas.
2. We haven't been in the opera forsince over a year.
3. I haven't spoken German forsince the end of the war.
4. You have kept me waiting forsince half an hour!
5. It is about two years forsince we last had news of him.
6. I haven't bought a new book forsince April.
7. We haven't seen our cousin forsince ages.
8. His wife has changed a lot forsince the last time we met.
9. My daughter hasn't written to me forsince my birthday.
10. We have lived here forsince many years.
11. It hasn't snowed here forsince six months.
12. Our guests have been sailing forsince tea-time.
13. It has been several hours forsince I had dinner.
14. There hasn't been any war in this country forsince over a century.
15. Nothing has been changed here forsince the Middle Ages.