1. left - past simple active.
2. will be - future simple active.
3. were speaking - past continious active.
4. studied - past simple active.
5. was spoken about - past simple passive.
6. will be studied - future simple passive.
7. am working - present continious active.
8. has been written - present perfect passive.
9. studies - present simple active.
10. are working - present continious active.
11. is being translated - present continious passive.
12. do ..work - present simple active.
13. saw - past simple active, was going - past continious active.
14. will have passed - future perfect active.
15. was written - past simple passive.
16. shall be writing - future continious active.
17. will have been done - future perfect passive, comes - present simple active.
18. translated - past simple active.
19. had been written - past perfect passive.