1.All had been celebrating for 2 hours, when the last guest came.
2. Children celebrated Halloween the last week.
3. What's the noise? - Neighbours are celebrating something.
4. Tomorrow all will have been celebrating for two hours before they will come.
5. In winter they will celebrate the 20th wedding anniversary.
6. They have been celebrating since yesterday.
7. By the time I came, all had celebrated and gone.
8. She celebrate their wedding anniversary that week.
9. They will have celebrated this event by the tomorrow evening.
10. My mum never celebrates her birthday
11. When you'll come, we have been celebrating the end of the course.
12. When I was writing essay yesterday , they were celebrating in a cafe.