Question

Fill the spaces in the following sentences by using one of these forms + the perfect infinitive of the verbs in brackets.
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.
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) £10. £5 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.

Answer 1

Must have been Must have been Needn't have helped Must have left Can't have escaped Needn't have given Couldn't have seen Must have started Must have been Needn't have bought