I) 1. I saw him get in through the window.

2. She had worked so hard that she made herself sick.

3. Though the traffic was bad, I arrived on time.

4. We were so late that we missed the first act of the play.

5. They’re the birds that I fed this morning.

6. I wish I knew many English words.

7. She asked me if I had many friends.

8. If we had a lot of money, we would buy a lot of new books

9. It is difficult to learn English.

10. John invited Sarah to his birthday party.

II) 1. The film was so boring that she decided to go home early.

2. It is such a difficult question that all the students can't answer it.

3. Mr. Brown wants to use solar energy but he does not have enough money to buy necessary equipment.

4. By the time Shakespeare died in 1616, he had written more than 37 plays.

5. Since Douglas fell off his bicycle last week, he has had to use crutches to walk.

6. I (had) turned off the lights before I left the room.