Ответ:
Упражнение 1.
To go - had you gone?
to do - had you done?
to know - had you known?
to make - had you made?
to read - had you read?
to take - had you taken?
to study - had you studied?
to translate - had you translated?
to write - had you written?
Упражнение 2.
1. What had Mary written?
2. What hadn't we received from you of late?
3. Which holidays had we spent?
4. How many books had you read this year?
5. Where had you left your watch?
6. What hadn't Mary turned off?
7. What had my sister helped me with?