Model verb exercise

<http://www.englishpage.com/modals/interactivemodal8.htm>
My score is 76%. I got 19 out of 25. 6 wrong sentenses left:

2. The book is optional. My professor said we could read it if we needed extra credit. But we [cannot / must not / don't have to] read it if we don't want to.
3. Susan [couldn't / can't / might not] hear the speaker because the crowd was cheering so loudly.
8. You [can't / couldn't / won't be able to] do the job if you didn't speak Japanese fluently.
11. You [may / would / might] eave the table once you have finished your meal and politely excused yourself.
18. I can't stand these people - I [have got to / might / had better] get out of here. I'm going to take off for awhile while you get rid of them.
21. Terry and Frank said they would come over right after work, so they [can / have to / should] be here by 6:00.

Here are my right sentenses:

1. Ted's flight from Amsterdam took more than 11 hours. He must be exhausted after such a long flight.
4. The television isn't working. It must have been damaged during the move.
5. Kate: Can you hold your breath for more than a minute?Jack: No, I can't.
6. You don't have to be rich to be a success. Some of the most successful people I know haven't got a penny to their name.
7. I've redone this math problem at least twenty times, but my answer is wrong according to the answer key. The answer in the book must be wrong!
9. You shouldn't worry so much. It doesn't do you any good. Either you get the job, or you don't. If you don't, just apply for another one. Eventually, you will find work.
10. You have to be kidding! That can't be true.
12. Jenny's engagement ring is enormous! It must have cost a fortune.
13. Shall we move into the living room? It's more comfortable in there and there's a beautiful view of the lake.
14. If I had gone white water rafting with my friends, I would be floating down the Colorado River right now.
15. At first, my boss didn't want to hire Sam. But, because I had previously worked with Sam, I told my boss that he ought to take another look at his resume and reconsider him for the position.
16. You had better take along some cash. The restaurant may not accept credit cards.
17. The machine can be turned on by flipping this switch.
19. You mustn't forget to pay the rent tomorrow. The landlord is very strict about paying on time.
20. Do you always have to say the first thing that pops into your head. Can't you think once in a while before you speak?
22. Yesterday, I had to cram all day for my French final. I didn't get to sleep until after midnight.
23. We shall no longer suffer the injustice of oppression! Freedom shall be ours!
24. If I had gone to the University of Miami, I could have participated in their Spanish immersion program.
25. The lamp might not be broken. Maybe the light bulb just burned out.

model verb exercise

<http://www.englishpage.com/modals/interactivemodal7.htm>
My score is 75 %, My these sentenses are wrong. Wrong ansers are bold, and right answers are red

5. The package [should have been delivered / should be delivering / should be delivered ]tomorrow afternoon. It was sent by express mail this morning.

7. You can't mean that! You [must joke / have got to be joking / have to have joked].

8. If Debbie hasn't come home yet, she [must still wait / must still be waiting / must still have waited] for us in the coffee shop.

12. If I had gone with my friends to Jamaica, I [could have taken / might be taken / ought to be taking] scuba diving lessons.

13. Margaret agreed to meet us at the entrance to the theater. She [ought to be waiting / ought to wait / ought to have waited] for us when we get there.

Here are my right sentences:

1. I'm not really sure where Beverly is. She might be sitting in the living room, or perhaps she's in the backyard.
2. Doug must have returned the video we rented on his way to work. It was on the table, but now it's gone.
3. You ought to check the air pressure in your tires. You don't want to get a flat tire on your trip.
4. The computer isn't working. It must have been damaged during production.
6. You have to book the tickets for the play in advance - they sell out quickly.
9. Mike decided not to join us for lunch. He had to stay at work to finish the marketing report.
10. If I had gone with my friends to Jamaica, I would be lying on a white sand beach right now.
11. If I had gone with my friends to Jamaica, I would not have had to come to work this week.
14. It might have been Sam who called and didn't leave a message on the answering machine. He said he wanted to get together with us this weekend.
15. The machine can be turned on by flipping this switch.
16. She might have been crying. That could have been why her eyes were so red and swollen.
17. If she was crying, she must have been very upset.
18. That painting might not have been painted by Picasso. It could be a forgery.
19. Your diving equipment must be cleaned regularly if you want to keep it in good condition.
20. If I hadn't taken a taxi, I might have been waiting for you at the train station for hours.

Review of Model verb

Level of certainty:
will/won't > may/ may not > might/mightn't

Summarise:

PRESENT/ FUTURE: model verb + bare infinitive

will or won't: event is certain to occur
must or can't/couldn't: most logical or rational outcome
should or shouldn't: want something to happen with a reasonable expectation
may or may not: something will possibly happen
might/could or mightn't: will possibly happen, but we are less certain (< color="#006600">PAST: model verb + have + Verb 3
model verb = the same in PRESENT / FUTURE

This website will be clearer than my summary.
<http://www.britishcouncil.org/learnenglish-central-grammar-modal-verbs.htm>