He said that
1. he wrote essays twice a week.
2. he was writing an essay then.
3. he had written essays since he had gone into the 5th form.
4. he had written two essays that week.
5. he had never written such difficult essays.
6. he had written an essay the day before.
7. he had already written an essay by 2 p.m. the day before.
8. he had been writing an essay at 2 p.m. the day before.
9. he had written an essay
the day before.
10. he had been writing an essay
for already 2 hours when I had come to him.
11. he would write an essay the following day.
12. he would be writing an essay at 3
p.m. the following day.
13. he would have been writing an essay for 2 hours when I came to him.
14. he would have written an essay by 2 p.m. the following day.