怎样使用情态动词shall/should/must

近些年来,高考的单项选择和短文改错中不断有考察情态动词shall/should/must的题干,而考生对于它们的用法并没有完全把握,因此,梳理shall/should/must的用法,给考生一个清晰的思路和全面的了解.——yes,I will.综上所述,在疑问句中征询对方意见,请求许可时：Shall常用于第一,第三人称; Can常用于第一,第二人称,也可以用could,回答仍用can; May常用于第一人称,也可以用might,否定答语mustn't; Will常用于第二人称,也可以用would,答语仍用will.1.2 shall用于二三人称的陈述句中表示说话人给对方命令,威胁,允诺（常见于法律,法规,条令） e.g SEFC Book2.unit19.The Merchant Of Venice INTEGRATING SKILLS Reading The MERCHANT OF VENICE(2) P:That is the law.You want justice.So you shall get justice,more than you wanted P:Wait,Shylock,The law of Venice says that if anyone tries to kill or murder any citizen of Venice,everything that he owns shall be taken away from him..One of his money and his goods shall be given to the city of venice and the other half shall given to the person he has tried to kill.His life shall be at the mercy of the Duke… e.g “The interest___be divided into five parts.”declared the judge.A.shouldB.mustC.shallD.can分析：这是过去高考中曾经考过的一道单项选择题,据语境“declared the judge”可知考察有关法律法规条文中表达命令语气的情态动词shall,所以答案选C,然而很多考生对shall这一用法没有掌握,错选A或B.2.关于should Should可以作为情态动词shall的过去式,但should作为情态动词,却有自己的用法.