must needn t needn t neednt must perfect infinitive must + perfect infinitive is used for affirmative deductions. can't/couldn't + infinitive is used for negative deductions. needn't + perfect infinitive is used for a past action which was unnecessary but was performed. Fill the spaces in the following sentences by using one of these forms + the perfect infinitive of the verbs in brackets. 1 Did you hear me come in last night? ~ No, I . . . (be) asleep. 2 I wonder who broke the wineglass; it . . . (be) the cat for she was out all day. 3 You . . . (help) him. ( You helped him but he didn 't need help.) 4 I had my umbrella when I came out but I haven't got it now. ~ You . . . (leave) it on the bus. 5 He . . . (escape) by this window because it is barred. 6 I . . . (give) Ј10. Ј5 would have been enough. 7 I saw a rattlesnake near the river yesterday. ~ You . . . (see) a rattlesnake. There aren't any rattlesnakes in this country. 8 He is back already. ~ He . . . (start) very early. 9 He returned home with a tiger cub. ~ His wife (be) very pleased about that. 10 I bought two bottles of milk. ~ You . . . (buy) milk; we have heaps in the house. 11 I phoned you at nine this morning but got no answer. ~ I'm sorry. I . . . (be) in the garden. 12 I left my bicycle here and now it's gone. ~ Someone . . . (borrow) it. 13 When she woke up her watch had vanished. ~ Someone . . . (steal) it while she slept. 14 I've opened another bottle. ~ You . . . (do) that. We've only just started this one. 15 The machine said, 'You weigh 65 kilos,' and I said, Thank you.' ~ You . . . (say) anything. 16 I told him to turn left and he immediately turned right! ~ He . . . (understand) you. 17 Perhaps he swam across. ~ No, he . . . (do) that; he can't swim. 18 Do you remember reading about it in the newspapers? ~ No, I . . . (be) abroad at the time. 19 He . . . (walk) from here to London in two hours. It isn't possible. 20 He was very sick last night. ~ The meat we had for supper . . . (be) good. 21 There was a dock strike and the liner couldn't leave port. ~ The passengers . . . (be) furious. 22 We went to a restaurant and had a very good dinner for Ј3. ~ You . . . (have) a very good dinner if you only paid Ј3. 23 I have just watered the roses. ~ You . . . (water) them. Look, it's raining now! 24 That carpet was made entirely by hand. ~ It . . . (take) a long time. 25 The door was open. ~ It . . . (be) open. I had locked it myself and the key was in my pocket. 26 He said that he watered the plants every day. ~ He . . . (water) them. If he had they wouldn't have died. 27 He came out of the water with little red spots all over his back. ~ He . . . (be) stung by a jelly-fish. 28 We've sent for a doctor. ~ You . . . (send) for him. I am perfectly well. 29 I've made two copies. ~ You . . . (make) two. One would have been enough. 30 There was a terrible crash at 3 a.m. ~ That . . . (be) Tom coming in from his party. 31 I had to get down the mountain in a thick fog. ~ That . . . (be) very difficult. 32 I saw Ann in the library yesterday. ~ You . . . (see) her; she is still abroad. 33 How did he get out of the house? He . . . (come) down the stairs for they were blazing. 34 You . . . (lend) him your map. He has one of his own. 35 I spoke in English, very slowly. ~ You . . . (speak) slowly. He speaks English very fluently. 36 He was found unconscious at the foot of the cliff. He . . . (fall) 200 metres.