OXFORD PRACTICE GRAMMAR-53 sau đây là giáo trình lý thuyết tiếng anh và bài tập áp dụng từ cơ bản đến nâng cao , nhằm giúp các bạn có thể tự mình ôn tập và củng cố thêm về nền tảng kiến thức môn Anh văn , tự tin đạt kết quả tốt trong kỳ thi ngoại ngữ | OXFORD PRACTICE GRAMMAR 53 IT MAY COULD MUST HAVE BEEN ETC A Introduction Vicky Emma and Matthew are at a club in town. Vicky Where s Daniel He should have been here half an hour ago. Emma He may have got lost. It isn t easy to find this place. Matthew He could have forgotten all about it I suppose. Emma He can t have forgotten. We were talking about it this morning. Matthew Well something must have delayed him. We can use a modal verb with the perfect have a past participle . We use this structure to talk about possible past events. B May have might have and could have We use these forms to say that possibly something happened in the past. He may have got lost. Perhaps he has got lost. You might have left your keys at work. Perhaps you left them at work. Someone could have stolen them. It is possible that someone stole them. We also use could have for an opportunity that we didn t take or a possible result that didn t happen. We could have gone out somewhere but we were too tired. You were very lucky. There could have been a terrible accident. Daniel may not have caught the bus. I expect he missed it. Perhaps he didn t catch it. 7 might not have locked the door. Perhaps I didn t lock it. Must have and can t have Must and can t are opposites. MUST HAVE My watch says it s only ten past two. It must have stopped. I realize it is certainly true that my watch has stopped. COULDN T HAVE It is impossible that something happened. Daniel couldn t have caught the bus. It doesn t run on Sundays. It is impossible for him to have caught the bus. CAN T HAVE You ve only spent five minutes on that job. You can t have done it properly. I realize it is impossible that you did the job properly. Should have and ought to have We use these forms when someone didn t do the right thing. We didn t play very well We should have played better. I got lost. Sorry. I ought to have drawn you a map. It was a lovely old building. They shouldn t have knocked it down. 29A Will have done 46 May .
