OXFORD PRACTICE GRAMMAR-56 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 56 ACTIVE AND PASSIVE 2 A The passive and the agent In a passive sentence we sometimes mention the agent the person or thing doing the action . We use by with the agent. The cheque must be signed by the manager. The medals were presented by Nelson Mandela. But we mention the agent only if it is important for the meaning of the sentence. Sometimes we do not mention it. 1 We do not mention the agent if it does not add any new information. All our money and passports were stolen. A man was arrested last night. We do not need to say that the money was stolen by a thief or that the man was arrested by the police . 2 We do not mention the agent if it is not important. The streets are cleaned every day. Oil has been discovered at the North Pole. Who discovered the oil is less important than the fact that it is there. 3 It is sometimes difficult to say who the agent is. This kind ofjacket is considered very fashionable these days. A number of attempts have been made to find the Loch Ness monster. B Empty subjects they people etc Compare these two sentences. ACTIVE They clean the streets every day. PASSIVE The streets are cleaned every day. The new and important information is how often the streets are cleaned. We are not interested in saying who cleans them. In the active sentence we can use the empty subject they. We sometimes use a sentence with an empty subject instead of the passive especially in conversation. We can also use the empty subjects people you one and someone. ACTIVE People use this footpath all the time. You One should check the details. Someone took my purse. PASSIVE This footpath is used all the time. The details should be checked. My purse was taken. When do we use the passive We use the passive in both speech and writing but it is more common in writing. We see it especially in textbooks and reports. We use it to describe activities in industry science and technology and also for official rules. Bananas are exported to Europe. .
