情态动词.ppt

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,Modal Verbs,Must,Must,，“必须”，“应当”,表推测时，用于 肯定,否定式,-mustnt,，“禁止”,E.g.America mustnt sell advanced,weapons toTaiWan.,Must I attend the exam?,Yes,you must.,No,you neednt/you dont have to.,Must(,主观,),只用于 一般现在时 一般将来时,Have to,（客观）任何时态,can,Can,“,能,”,，,”,会,”,表推测时，主要用于 否定 疑问,E.g.I believe her.She cant be such a,boring girl.,Can I drive the car?,Yes,you can/may,No,you cant.youd better not.You mustnt.,Can(,能力,),只有现在时，过去式,Be able to,（结果）有各种时态,may,May,“,可以,”,表推测时，可能性小,May I come in?,Yes,you may/can,No,you may not/cant,youd better not/Im afraid not,you mustnt,May+V/may+be+V-ing,对现在将来推测,对过去推测,May+have+done,