1. i am writing
2. i was writing
3.is sleeping
4. was not sleeping
5.are not doing, the are playing
6.were not doing
7. was not reading
8.is not reading
9.is going
10. are you doing, i am drinking
11.were you drinking, was not drinking
12.was reading, is reading
13.is playing
14.were shining, were singing
15.are you eating