Certainty, possibility, deduction: CAN, COULD, MAY, MIGHT, MUST, WILL, SHOULD, OUGHT TO Something possible to do at any time: can - may Suitcases can/may be left in the left luggage office at the station. Jenny may swing by if she remembers. Future possibility: may – might – could (could refers to a theoretical possibility) The parcel may/might arrive tomorrow. She could work with us if we ask her
Present or future certainty: will + simple or continuous verb: You can phone Sally: shell be at home now. Ill be there by 9 oclock. The meeting will start at 7.30. We should go now: theyll be waiting for us. Ill be standing on the platform when you arrive. Possibility in the present: may – might- could + base form verb(usually the verb be) orcontinuous infinitive: Wheres Tony? T dont know. He may be outside. Alisons not in the office today so she may be working at home.
Possibility in the past: may - might - could + perfect form (simple or continuous): Its 8.30 so she may have left by now. Sue wasnt at the party last night. She might have been feeling too tired to come. To make a deduction about something in the present:use must (Positive) can’t (Negative) + base form or continuous verb Janes not at home so she must be on her way here. Barbaras back at work now so she must be feeling better. The office is closed now so he cant be there. He cant be driving here: he hasnt got a car.
Deduction about something in the past: must or cant (or couldnt) + perfect form Its very wet outside so it must have rained in the night. You must have been talking on the phone for a long time last night. Eddie couldnt have done that robbery: he was with me the whole weekend. Should or ought to + base form to make assumptions about the present or the future Should or ought to + base form to make assumptions about the past. Should more frequent than ought to: The train got in half an hour ago so they should be here soon. The suns been shining all day so the sea should be quite warm now. The weathers lovely there at this time of year so they should be having a nice holiday. Lets go and see Cathy: she ought to have finished working by now.
Practice 1Rewrite the following sentences using a modal.The underlined words can be written as subject + modal + verb (or modal + subject + verb inquestions). In some sentences, more than one modal is possible.11 I promise to phoneI promise to phone you next week.you next week.2 At the age of nine, he still2 At the age of nine, he still didnt know how to readdidnt know how to read..33 Its essential that we leaveIts essential that we leave on time tomorrow morning.on time tomorrow morning.44 Are you able to comeAre you able to come with me tonight?with me tonight?55 Its not a good idea for you to workIts not a good idea for you to work so hard.so hard.66 Its possible that theyll beIts possible that theyll be here soon.here soon.77 Why dont we goWhy dont we go and see a film tonight?and see a film tonight?
Practice 2Complete the sentences with can, could, may, might, will, should, oughtto or must and the appropriate form of the verb.1. Kerrys rather late. She ……………………… (miss) the train.2. Travellers checks …………………………..(be exchanged) at most banks.3. Theyre not answering the phone so they …………………………………. (be) out.4. 4. Dont phone her now. It …………………………….. (be) the middle of the night inAustralia.5. 5. They ………………………………. (not move) house yet. I saw them in town thismorning.6. 6. I havent seen Molly this week. I think she …………………………… (visit) herparents but Im not sure.7. 7. Her exam results are coming out soon. She worked very hard so she ………………..(do) well