人教版高中英语必修三unit1festivalsaroundtheworldperiod2课件

人教版高中英语必修三unit1festivalsaroundtheworldperiod2课件内容摘要：

might be at home now. Helen may go on the trip with us, but she isn’t very sure yet. She may / might have read it in the paper. He may not have finished reading the book. 情态动词 用 法 will 表请求 （第二人称） 表意志 ,意愿 表某种倾向或习惯 would 更客气的 请求 过去的意志 ,意愿 过去的倾向或习惯 If you will help me with my English, I will be very happy. I promised that I would do my best. Will you tell me something about your hometown? Would you please speak again more slowly? He will always take a walk after supper. During the vacation he would often visit me. 情态动词 用 法 shall 征求对方意见 （第一，三人称） 表示命令，警告，威胁或允诺 （第二， 三人称） should / ought to 表示劝告 ,建议 ,命令或责任 “应该，必须” 表示推测，“理应， 估计，大概，可望” should 还可表示“竟然” Shall we start off now? You shall do as I say. Tell him that he shall have the book tomorrow. You shall be punished if you do that again. You shouldn’t /oughtn’t to smoke so much. She shouldn’t have left without saying a word. It’s five o’clock. John should be at home now. We have prepared a fridge of good and drinks. That ought to be enough for the party. It’s a pity that he should be so rude to a lady. 情态动词 含义 否定式 注意点 must 表必要 “必须” needn’t “不必” ( 区别 have to) 有时表“ 偏要 ” 表推测 “一定” can’t “不可能” 只能 用于 肯定 句，不能 用于 否定、疑问句 — Must I finish all assignments at a time? —Yes, you must. / No, you needn39。 t. I don’t like this TV set. We must buy a new one. There was no more bus. They had to wa。