EX1:

1. has never seen

2.remembered/forgot

3.sold

4.you had put/went

5.have not seen

6.has done

7.realized/ had forgotten

8.have never seen

9.arrived/has just gone

10.was/ has met

EX2:

1. when we arrived, he had gone home

    +after he had gone home, we arrived

2. after having a snack, we had a look around the shop

3. the had no sooner begun work than the light failed

  +No sooner had the light failed than they began work

  +Hardly had they begun work when the light failed

4. we were happier than everyday before

5.before i had seen a real tiger for the first time, i went to the zoo

7.if the man had not been poor, he could have  afforded accommodation

6.i would rather you had not gone to the party yesterday