28. Must and Can’t ENGLISH GRAMMAR IN USE FOR INTERMEDIATE

ENGLISH GRAMMAR IN USE FOR INTERMEDIATE

28. Must and Can’t

A

Study this example: You can use must to say that you believe something is certain: ·         You've been travelling all day. You must be tired. (Travelling is tiring and you've been travelling all day, so you must be tired.) ·         'Joe is a hard worker.' 'Joe? You must be joking. He doesn't do anything.' ·         Louise must get very bored in her job. She does the same thing every day. ·         I'm sure Sally gave me her address. I must have it somewhere. You can use can't to say that you believe something is not possible: ·         You've just had lunch. You can't be hungry already. (People are not normally hungry just after eating a meal. You've just eaten, so you can't be hungry.) ·         They haven't lived here for very long. They can't know many people. Study the structure: I/you/he (etc.) must can’t be (tired/hungry/at work etc.) be (doing/going/joking etc) do/get/know/have etc

B

For the past we use must have (done) and can't have (done). Study this example: Martin and Lucy are standing at the door of their friends' house. They have rung the doorbell twice, but nobody has answered. Lucy says: They must have gone out. ·         'We used to live very near the motorway.' 'Did you? It must have been noisy.' ·         'I've lost one of my gloves.' 'You must have dropped it somewhere.' ·         Sarah hasn't contacted me. She can't have got my message. ·         Tom walked into a wall. He can't have been looking where he was going. Study the structure: I/you/he (etc.) must can’t have been (asleep/ at work etc.) been (doing/looking etc.) gone/got/known etc. You can use couldn't have instead of can't have: Sarah couldn't have got my message. Tom couldn't have been looking where he was going.

EXERCISES

28.1	Put in must or can't. 1 You've been travelling all day. You __must____ be tired. 2 That restaurant ______ be very good. It's always full of people. 3 That restaurant _____ be very good. It's always empty. 4 I'm sure I gave you the key. You _____ have it. Have you looked in your bag? 5 I often see that woman walking along this street. She _______ live near here. 6 It rained every day during their holiday, so they _________ have had a very nice time. 7 Congratulations on passing your exam. You _________ be very pleased. 8 You got here very quickly. You _____________ have walked very fast. 9 Bill and Sue always stay at luxury hotels, so they __________ be short of money.
28.2	Complete each sentence with a verb (one or two words). 1 I've lost one of my gloves. I must ___ have dropped ____ it somewhere. 2 Their house is very near the motorway. It must _____be____ very noisy. 3 Sarah knows a lot about films. She must _________to the cinema a lot. 4 I left my bike outside the house last night and now it's gone. Somebody must _________ it. 5 'How old is Ted?' 'He's older than me. He must ____________ at least 40.' 6 I didn't hear the phone ring. I must ____________asleep. 7 A: You're going on holiday soon. You must ___________ forward to it. B: Yes, it will be really good to get away. 8 The police have dosed the road, so we have to go a different way. There must _________ an accident. 9 I'm sure you know this song. You must __________ it before. 10 There is a man walking behind us. He has been walking behind us for the last 20 minutes. He must __________ us.
28.3	Read the situations and use the words in brackets to write sentences with must have and can't have. 1 We went to their house and rang the doorbell, but nobody answered. (they /go out) ______ They must have gone out ___________________ 2 Sarah hasn't contacted me. (she /get /my message) ______ She can’t have got my message ______________ 3 The jacket you bought is very good quality. (it /very expensive) 4 I haven't seen our neighbours for ages. (they /go away) 5 I can't find my umbrella. (I /leave /it in the restaurant last night) 6 Amy was in a very difficult situation when she lost her job. (it /easy for her) 7 There was a man standing outside the cafe. (he /wait /for somebody) 8 Rachel did the opposite of what I asked her to do. (she /understand /what I said) 9 When I got back to my car, the door was unlocked. (I /forget /to lock it) 10 I was woken up in the night by the noise next door. (my neighbours /have /a party) 11 The tight was red, but the car didn't stop. (the driver /see /the red tight)

ANSWER KEY

28.1 2 must          6 can't 3 can't           7 must 4 must          8 must 5 must           9 can't 28.2 3 go 4 have taken /have stolen /have moved 5 be 6 have been 7 be looking 8 have been 9 have heard 10 be following 28 .3 3 It must have been very expensive. 4 They must have gone away. 5 I must have left it in the restaurant last night. 6 It can't have been easy for her. 7 He must have been waiting for somebody. 8 She can't have understood what I said. or She couldn't have understood what I said. 9 I must have forgotten to lock it. 10 My neighbours must have been having a party. 11 The driver can't have seen the red light. Or The driver couldn't have seen .