OXFORD PRACTICE GRAMMAR-48 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 48 NECESSITY MUSTN T NEEDN T ETC A Mustn t or needn t We use must to say that something is necessary see Unit 47 . You must be careful with those glasses. I must remember my key. Now compare mustn t and needn t. MUSTN T NEEDN T We use mustn t to say that something is We use needn t when something is not necessary a bad idea. You mustn t drop those glasses. They ll break. You needn t wash those glasses. They re dean. I mustn tforget my key or I won t get in. We needn t make sandwiches. There s a cafe. You mustn t wear your best clothes. You ll get You needn t wear your best clothes. You can wear them dirty. what you like. B Don t have to and don t need to We can use don t have to and don t need to when something is not necessary. The meaning is the same as needn t. You don t have to don t need to wash those glasses. They re clean. Mark doesn t have to doesn t need to finish the report today. He can do it at the weekend. For American usage see page 379. For the past we use didn t. The food was free. We didn t have to pay We didn t need to pay for it. C Didn t need to or needn t have Daniel hadn t booked a seat but luckily the train wasn t full. He didn t need to stand. DIDN T NEED TO We use didn t need to when something was not necessary. Standing was not necessary because there were seats. Mark didn t need to hurry. He had lots of time. He drove slowly along the motorway. We didn t need to go to the supermarket because we had plenty of food. Sometimes we can use didn t need to when the action Mark didn t need to hurry but he drove at top speed. Trevor and Laura booked a table for dinner. But the restaurant was empty. They needn t have booked a table. NEEDN T HAVE We use needn t have a past participle for something we did which we now know was not necessary . booking a table. Mark needn t have hurried. After driving at too speed he arrived half an hour early. We needn t have gone to the supermarket. We already had a pizza for tonight. .
