《2021英语语法 情态动词+ HAVE +过去分词+词汇比较用法》由会员分享，可在线阅读，更多相关《2021英语语法 情态动词+ HAVE +过去分词+词汇比较用法（6页珍藏版）》请在金锄头文库上搜索。
1、英语语法 情态动词+ have +过去分词+词汇比较用法 高二是高中学习的关键时期，不仅课程任务重，而且很大程度上决定着学生今后的发展方向，以及能否考入理想的大学。有着丰富教学经验的老师，向大家传授高二各学科学习技巧，希望对高二学生掌握良好的学习方法、提高学习效率有所帮助。以下是英语学科的主要学习方法。 比较have to 和must的用法 1) 两词都是必须的意思，have to 表示客观的需要， must 表示说话人主观上的看法，既主观上的必要。 My brother was very ill, so I had to call the doctor in the middle of th
2、e night. 我弟弟病得很厉害，我只得半夜里把医生请来。(客观上需要做这件事) He said that they must work hard. 他说他们必须努力工作。(主观上要做这件事) 2) have to有人称、数、时态的变化，而must只有一种形式。但must 可用于间接引语中表示过去的必要或义务。 He had to look after his sister yesterday. 3) 在否定结构中： dont have to 表示不必 mustnt 表示禁止， You dont have to _ him about it. 你不一定要把此事告诉他。 You mustnt
3、_ him about it. 你一定不要把这件事告诉他。 比较can 和be able to 1)can could 表示能力;可能 (过去时用could), 只用于现在式和过去式(could)。be able to可以用于各种时态。 They will be able to _ you the news soon. 他很快就能告诉你消息了。 2)只用be able to a. 位于助动词后。 b. 情态动词后。 c. 表示过去某时刻动作时。 d. 用于句首表示条件。 e. 表示成功地做了某事时，只能用was/were able to， 不能用could。 He was able to fl
4、ee Europe before the war broke out. = He managed to flee Europe before the war broke out. 注意：could不表示时态 1)提出委婉的请求，(注意在回答中不可用could)。 - Could I have the television on? - Yes, you can. / No, you cant. 2)在否定，疑问句中表示推测或怀疑。 He couldnt be a bad man. 他不大可能是坏人。 1) may(might) have + done sth, can (could) have
5、+ done sth 表示过去，推测过去时间里可能发生的事情。 Philip may (might) have been hurt seriously in the car aident. Philip can (could) have been hurt seriously in the car aident. 2)must have +done sth，对过去时间里可能发生的事情的推测，语气较强，具有肯定，谅必的意思。 -Linda has gone to work, but her bicycle is still here. -She must have gone by bus. 3)
6、 ought to have done sth, should have done sth 本应该做某事，而事实上并没有做。否定句表示不该做某事而做了。 You ought to (should) have been more careful in this experiment. He ought not to have thrown the old clothes away.(事实上已扔了。) ought to 在语气上比should 要强。 4) neednt have done sth 本没必要做某事 I dressed very warmly for the trip, but I neednt have done so. The weather was hot. 5) would like to have done sth 本打算做某事 I would like to have read the article, but I was very busy then. 模板,内容仅供参考
