Test 1. 1. should/ought to; 2. must; 3. may/can/could; 4. needn’t; 5. mustn’t/can’t; 6. mustn’t/shouldn’t; 7. can’t; 8. has; 9. mustn’t/can’t; 10. needn’t; 11. may; 12. may; 13. may; 14. shall; 15. should; 16. may; 17. should; 18. shall; 19. mustn’t/shouldn’t; 20. may

Test 2. 1. a; 2. b; 3. b; 4. a; 5. c; 6. a; 7. c; 8. b; 9. c; 10. a; 11. b; 12. c; 13. a; 14. c; 15. a; 16. c; 17. b; 18. a; 19. b; 20. c

Test 3. 1. should; 2. should; 3. Do you have to; 4. should; 5. had to; 6. should; 7. have to; 8. has to; 9. should; 10. have to; 11. has to; 12. had to; 13. should; 14. don’t have to; 15. should; 16. should; 17. doesn’t have to; 18. had to; 19. have to; 20. should

Test 4. 1. mustn’t; 2. can; 3. had to; 4. don’t have to; 5. should; 6. must; 7. needn’t; 8. could; 9. had to; 10. couldn’t; 11. must; 12. might; 13. May; 14. doesn’t have to; 15. can’t; 16. ought to; 17. were able to; 18. couldn’t; 19. must; 20. could

Test 5. 1. can; 2. should; 3. can; 4. should; 5. can; 6. ought; 7. should; 8. have; 9. should; 10. need

Test 6 (The following are possible answers. Other variants are often possible.) 1. He must have already been learning this poem for an hour. 2. You should have forgotten about it long ago. 3. The bus was to arrive 5 minutes ago. 4. He can’t be busy now. 5. He may/might be able to help you. 6. You needn’t come tomorrow./You don’t have to come tomorrow. 7. He must have had to do it. 8. Could you repeat your question, please? 9. I may/ might have to work on Sunday. 10. He must be still doing his homework. 11. You should finish this work. 12. I will be able to speak English very well in a year. 13. What did you have to do yesterday? 14. May I go out? 15. He was to come an hour ago. 16. Can he have forgotten about my birthday? 17. The teacher said we might go home. 18. You mustn’t read this book. 19. Last year I couldn’t swim but now I can. 20. He may be still waiting for me.