NOTES: can, could, be able to: Can is often used with the verbs of sensual perception: hear, see, smell, taste, feel, + remember, understand: We could see the lake. I could smell gas. We couldn´t hear very well. We use could for general ability, for specific situation of in the meaning of manage, we use was/were able to: My grandfather could speak 5 languages. Fortunately everybody was able/managed to escape. We were able/managed to find the exit. We use could in the meaning of may/might (=possibility): The story could/may/might be true. We use should + present infinitive to express what is a good thing to do – advice, opinion: The government should do more to reduce crime. We use should + past infinitive to express that something wasn´t done, but it would have been the right thing to do: I wonder why they are so late. They should have arrived long ago. EXERCISES: A1/ Read the rules of the Fitness Centre. Complete what the instructor says with must/n´t/, need/n´t/, or should/n´t/. SPORTS CLUB NOTICE: o It is vital to have a health check before using the gym for the first time. o It isn´t necessary for members to pay for towels, but guests are charged USD1 per towel. o It is recommended that you begin with light exercise ¨s to warm up. o It is not recommended that you exercise after a heavy meal. o It is a good idea to ask a member of staff if you´re not sure how to use the equipment. o It is forbidden to use the Fitness Centre against the advice of the staff. You................have a health check before using the gym for the first time. You..........................pay for towels, but your guests ..............................pay USD 1. You ..........................begin with light exercises to warm up. You............................exercise after a heavy meal. You............................ask a member of staff if you´re not sure how to use the equipment. You..........................use the Fitness Centre against the advice of the staff. A2/ Read what James did. Then complete the sentences with mustn´t, needn´t , or shouldn´t: James became a member of the Sports Club yesterday. He used the gym without having a health check. He paid for a towel. He didn´t begin with light exercises. He exercised soon after eating a big lunch. He didn´t ask a member of staff how to use the equipment. His back is very painful today. James..............................have used the gym without having a health check. He......................................have paid for a towel. He................................have begun with light exercises. He................................have exercised soon after lunch. He.................................have asked a member of staff how to use the equipment. He................................have injured his back. B/ Tick the pairs of sentences that express approximately the same idea. Put a cross by those where there is a clear difference in meaning: This could be the chance we have all be waiting for. This might be the chance we have all be waiting for. This may be the last chance for peace. This might be the last chance for peace. I must be on my way if you don´t mind. You must be joking. They must have taken a short cut to get here. They had to take a short cut to get here. The washing machine shouldn´t be making such a noise. The washing machine couldn´t be making such a noise. It can´t be that difficult. It mustn´t be that difficult. Rewrite the following sentences using may, may not, can´t and must without changing the meaning /there may be more possibilities/: 1. It is possible they don´t live here any longer. 2. It is sure there is some mistake. 3. I am positive that they sold all the flowers. 4. It is possible that they are not married. 5. I am not quite sure if she gave up her job. 6. Maybe they did not finish the work. 7. He certainly did not give his speech yesterday. What can you deduce from the following situations? Example: Alice is on her hands and knees. – She might be looking for something. She might have dropped a contact lens. o The neighbours are making a lot of noise. o Penny´s phone bill is enormous. o Peter has got a black eye. o John has lost a lot of weight recently. o A car is found crushed into a tree, with the driver unconscious at the wheel. Use your own ideas to complete the sentences: 1. In most countries motorcyclists must..................................................................... 2. I nearly overslept this morning. I should have........................................................ 3. The plane lost one engine, but luckily the pilot was able to.................................... 4. Politicians ought not to............................................................................................. 5. I don´t really like this job so I might......................................................................... 6. Lots of friends passed the exam, so it can´t be ........................................................ 7. If you really want to get fit, you should................................................................... 8. We were so short of money we had to..................................................................... 9. I don´t know why you didn´t get my letter. It must have.......................................... 10. The car broke down but luckily we were able to...................................................... 11. I could...............................when I was ten, but I couldn´t ........................................