新概念一第125-126课精品课件.ppt

2. have to 表示“不得不”、“必须”，后接动词原形。 e.g 太晚了，我必须走回家。 It’s too late. I have to walk home. e.g. 他每天必须先给花园浇水。 He has to water the garden first. e.g. 昨天他不得不早点离开。 He had to leave early yesterday. 1） have to 的第三人称单数形式是：has to He/ She/ It/Tom/ My father/ has to 2) have to 和has to 的过去式：had to 2. have to 表示“不得不”、“必须”，后接动词原形。 e.g 他们今天不必完成这个工作。 They don’t have to/need to finish the work today. 4）一般疑问句：Do/Does/Did +主语+have to do ···？ e.g. 你必须早点走吗？ Do you have to leave early？ 肯定回答： Yes, I do. / Yes, I have to. / Yes, I must. 否定回答: No, I needn’t./No, I don’t have to/ need to. 3） 否定： have to--- don’t have to/don’t need to has to --- doesn’t have to/doesn’t need to had to --- didn’t have to/ didn’t need to 都表示 “不必” Must I take care of my grandma? Yes, you ____./No, you ______. (must; neednt) Does she have to come home before 7? Yes, she _____./No, she __________. (has to; doesnt have to/neednt) Exercise 3. must 与have to 的区别 1）：must多表示主观意志，是从说话人的角度出 发谈必 须做某事。而have to强调客观需要。 I must finish my homework today. I have to finish my homework before lunchtime. Grammar We must take a taxi. 我们必须乘坐出租车。 （我们觉得有必要乘坐） We have to take a taxi. 我们不得不乘坐出租车。 （因为没有其他交通工具） 练一练： 我必须努力工作。(我觉得有必要这么做。) I must work hard. 我昨晚不得不乘船回家。(有可能没有赶上其他的航班或者火车，没选择才坐船。) I had to go home by ship last night. 2): 二者否定式的意义大不相同。have to 的否定式表示“不必”，而must not/mustn’t表示“不准，禁止”。 I don’t have to/need to finish my homework now. You mustn’t be late for school. 否定句翻译： 你不必要把此事告诉他。 You don’t have/need to tell him about it.　 你一定不要把这件事告诉他。 You mustn’t tell him about it.　　　　 你不能在医院吸烟。 You mustn’t smoke in the hospital. 你不必现在回答这个问题。 She doesn’t need/have to answer the question now. 3): must没有时态变化，而have to 可有不同的时态变化。 1). 我们明天必须出发。 We will have to leave tomorrow. 2). Tom昨天必须完成作业。 Tom had to finish his work yesterday. 总结 She has to leave early. She must leave early. S