情态动词had better.docx

情态动词had better,should,ought to用法点击一、 情态动词 had better1. had better 表示“最好”，其缩写为“ d better”,表示“有义务做某事”。例如： He warned me that I had better not say anything about it.他警告我对此事最好只字不提。 The matter had better be left as it is.这事最好任其自然。2. had better 表示提出建议、劝告或命令等，含有“应该做某事”之意，一般适用于对晚辈、平辈。例如：I thought you had better have my opinion first.我想你最好先听听我的意见。Its very cold outside. Youd better put on more clothes.外面很冷，你做好多穿些衣服。3. had better 否定形式为had better not,疑问句中had better 的否定形式有两种：Hadnt + 主语 +better + 动词原形；Had + 主语 + better not +动词原形。例如： Hadnt you better go with them? 你跟他们去不是更好吗？ Had we better not go? 我们不去不是更好吗？4. Had better do sth. 有时可省略为 better do sth. 例如： Better stay at home and have a good rest. 最好呆在家中好好休息。二、 情态动词 should, ought to1. Should 作情态动词，表示劝告、建议，多指主观上有责任、有义务做某事，作“应该”解，语气比 ought to要弱。例如：You should keep your promise.你应该履行诺言。You should study first aid with the teacher.你应该跟老师学习急救法。2. Ought to 表示客观上有责任、有义务做某事或非常可能的事，语气较强。其否定形式为 ought not to。例如：You ought to drink plenty of water.你应该大量喝水。You ought not to put any oil on the skin if it is burned. 如果皮肤烧伤，你不应该往上搽油。3. Should , ought to 用于疑问句时， should 直接放在主语前，而ought 变疑问句时则把 ought 放在主语前，to放在主语后的动词前。例如：Should I open the window? 我应该打开窗户吗？Ought he to go?他应该去吗？Yes, I think he ought to. 是的，我想他应该。4. Should 与 ought to 还可以表示推测，表示说话者根据某种情况做出的肯定推测，其意义为“应该”。例如：The wind has stopped blowing; it should be warmer. 风停了，天气该暖和了。If she took the 9:30 a.m. train, she ought to be arriving now. 假如她搭上早9:30 的火车，现在应该快到了。5. Should 还可以用于动词 suggest, insist, order, demand 等宾语从句的虚拟语气中。例如：I suggest that he apply for the job.我建议他申请这份工作。She insisted that Tom should not take part in the meeting. 她坚持要求汤姆不应该来参加会议。6. “should / ought to + have + 过去分词”则表示本应该做某事而实际上未做，含有“责备”的意味。例如：You shoul