考研英语：语法(情态动词-have to).docx

考研英语：语法(情态动词-have to)have to　　have to加动词原形　　表示"不得不"、"必需"的概念它比must更含有"客观条件使得必需如此做"的`意思，并有较多的时态如：　　Mr. Johnson has to work very hard to earn a living.约翰逊先生为了谋生不得不舍命干活　　I had to leave the party early last night. I wasn't very well.昨晚我只得早点离开晚会，我不大舒适　　We will have to get up very early tomorrow.我们明天必需起得很早　　I shall have to go to the clinic today for my bad cough.我咳嗽得厉害，今日必需去诊疗所看看　　[注]口语中的I have got to，you have got to等：I have to，you have to. Have I got to?和Do I have to?这两种疑问形式均可用。

　　shall　　shall作为情态动词用于其次、三人称　　可表示说话人给对方的"吩咐"、"警告"、"承诺"、"威逼"等概念如：　　You shall do it，whether you want to or not. 不管你情愿不情愿，你必需做这项工作吩咐)　　You shall have the book as soon as I finish it.这本书我一看完就给你承诺)　　You shall pay for it.你肯定会受到惩处的威逼)　　在疑问句中，情态动词shall用于第一、三人称　　表示说话人征求对方的看法或向对方请示如：　　What shall I do now? 我现在该做什么?　　Shall we go for a walk? 我们去漫步好吗?　　Shall he come tomorrow? 你要他明天来吗?　　should　　情态动词Should表示"劝说"、 "建议 "时　　这时should常译作 "应当"如：　　We Should learn about the computer and make full use of it.我们应当了解计算机并加以充分利用。

　　You should listen to the doctor's advice.你应当听大夫的话　　You should study the article care fully. 你应当细，心学习这篇文章　　should还可以表示 "预料"、"可能"　　They should be here by now.他们现在可能到了　　The reference book should be in the reading-room.这本参考书可能在阅览室里　　should有时表示说话人的感情如惊异、生气、悲观等　　Why should I go? 我干吗要去?(不满)　　I am sorry that he Should be so obstinate.我很缺憾，他竟这样固执悲观)　　It's strange that it should be so hot today.很怪，今日怎么这么热惊异)　　should后跟动词的完成式时　　这时句子指的是过去的事情假如是确定句，常说明某件事本应完成而未完成;假如是否定句，表示发生了不应当发生的事情.如：　　You should have stopped at in red light. 你见了红灯本应当停车。

　　You Should not have gone back to work without the doctor's permission.你不应当未经医生许可就回去工作　　He Should have come earlier. 他应早一点来考研英语：语法大全(情态动词-have to)】。