4. Use the appropriate form of the Infinitive (Active or Passive).
1. She only pretends . She isn’t easy .(frighten, frighten)
2. He is sorry way to panic then. (give)
3. I am glad to you at the party yesterday. (introduce)
4. I didn’t expect ___ this question. (ask)
5. Don’t talk too much if you want ___. (listen to)
6. Unpleasant things shouldn’t .(put off)
7. He is happy through with this task. (be)
8. It’s bad of you so much attention to trifling matters. You should be more serious. (pay)
9. Dan is happy ___ first prize for this picture. (award)
10. He is sorry ___ your advice then. (not follow)
11. There are a hundred things ___. (do)
12. According to the schedule the plane was long ago. (land)
13. It’s sensible of John Kate this advice. I hope she’ll follow it. (give)
14. He is sorry you in your work. (disturb)
15. It’s thoughtful of you the flowers. She was pleased. (bring)
16. He claims Elvis Priestly. Who’ll believe him? (meet)
17. Aren’t you supposed after your sister at the moment? (look)
18. I am sorry you but I didn’t mean anything of the kind. (disappoint)
19. It was considerate of my son __ of me when I was ill. (take care)
20. The woman pretended ___ and not the bell. (read, hear)
21. Ann would love ___ on the beach now instead of typing letters. (lie)

1. She only pretends to frighten. She isn't easy to frighten.
- In the first sentence, we need to use the infinitive form of the verb "frighten" after "pretends to" because it indicates the action that she is pretending to do. In the second sentence, we use the infinitive form "to frighten" after "isn't easy" to show the difficulty of frightening her.

2. He is sorry to give way to panic then.
- In this sentence, we need to use the infinitive form "to give" after "sorry" to express the action he is sorry for.

3. I am glad to introduce you at the party yesterday.
- Here, we need to use the infinitive form "to introduce" after "glad" to show the action that I am glad to do. However, the past tense "yesterday" indicates that the action of introducing already took place.

4. I didn't expect to be asked this question.
- In this sentence, we need to use the passive form of the verb "ask" (be asked) after "expect" because the subject is not doing the action of asking but receiving it.

5. Don't talk too much if you want to be listened to.
- Here, we need to use the passive form "to be listened to" after "want" to show the desired action of being listened to.

6. Unpleasant things shouldn't be put off.
- In this sentence, we use the passive form "be put off" after "shouldn't" to show that unpleasant things should not be postponed.

7. He is happy to be done with this task.
- Here, we use the passive form "to be done" after "happy" to show that he is pleased that the task is completed.

8. It's bad of you to pay so much attention to trifling matters. You should be more serious.
- In this sentence, we need to use the infinitive form "to pay" after "bad" to express the action that is considered bad. Additionally, after the comma, we use the verb "be" followed by the comparative adjective "more serious" to emphasize the desired behavior.

9. Dan is happy to be awarded first prize for this picture.
- Here, we use the passive form "to be awarded" after "happy" to show that Dan is pleased to receive the first prize.

10. He is sorry not to follow your advice then.
- In this sentence, we need to use the infinitive form "to follow" after "sorry" to express the action he is sorry for not doing.

11. There are a hundred things to do.
- Here, we use the infinitive form "to do" after "things" to indicate the actions that need to be done.

12. According to the schedule, the plane was landed long ago.
- In this sentence, we need to use the passive form "was landed" to indicate that the plane was the subject of the action rather than performing the action.

13. It's sensible of John to give Kate this advice. I hope she'll follow it.
- Here, we need to use the infinitive form "to give" after "sensible" to express the action that John did, which is considered sensible.

14. He is sorry to disturb you in your work.
- In this sentence, we use the infinitive form "to disturb" after "sorry" to express the action he is sorry for doing.

15. It's thoughtful of you to bring the flowers. She was pleased.
- Here, we use the infinitive form "to bring" after "thoughtful" to express the action that is considered thoughtful.

16. He claims to have met Elvis Priestly. Who'll believe him?
- In this sentence, we use the infinitive form "to have met" after "claims" to express the action that he claims to have done. Additionally, the question "Who'll believe him?" is used to express doubt or skepticism.

17. Aren't you supposed to be looking after your sister at the moment?
- Here, we use the infinitive form "to be looking" after "supposed" to express the action that the person is expected or supposed to do.

18. I am sorry to disappoint you, but I didn't mean anything of the kind.
- In this sentence, we use the infinitive form "to disappoint" after "sorry" to express the action that I am sorry for doing.

19. It was considerate of my son to take care of me when I was ill.
- Here, we use the infinitive form "to take care" after "considerate" to express the action that my son did, which is considered considerate.

20. The woman pretended to read and not to hear the bell.
- In this sentence, we use the infinitive form "to read" and "to hear" after "pretended" to express the actions that the woman pretended to do.

21. Ann would love to lie on the beach now instead of typing letters.
- Here, we use the infinitive form "to lie" after "would love" to express the action that Ann would love to do.