“情态动词+have done”表推测一览表情态动词+ have done用法例句must have done一定已经做了They must have finished their work.can’t have done不可能已经做了They can’t have finished their workcould have done可能已经做了或原来可能做但未做You could have used my computer because I didn’t use it.may have done也许已经做了They may have finished their work.might have done也许已经做了或原来可以做但未做You might have used my computer because I didn’t use it。Should/ought to have done原来该做但未做You Should have studied hard。need not have done原来不必做但做了You need not have gone out.would rather have done过去宁愿做但未做I would rather not have gone there.would like to have done过去想做但未做I would like to have seen the film。had better have done当时最好做了某事You’d better have gone there。“情态动词+be doing”表推测一览表情态动词+ be doing用法例句must be doing一定正在做They must be watching TV now。can’t be doing不可能正在做They can’t be watching TV now。May/might be doing也许正在做They may be watching TV now.口诀:“情动”加上 have done，推测事情已经干； “情动”加上 be doing,推测事情在进行；情态动词+have done 表推测一、must have done 一定已经做了.They must have finished their work.他们一定做了他们的工作.二、1、Can have done。可能已经做了。2、C an ’ t have done。不可能已经做了。They can have finished /homework so quickly.他们可能很快完成他们的工作。They can ’ n have finished /homework so quickly.他们不可能很快完成他们的工作。They can have gone to bed /since /the door is closed.门关着，他们可能已经睡着了。 完成时态+since三、1、Could have done.可能已经做过。（对过去事情的推测）2、C ouldn ’ t have done. 不可能已经做过。You could have used my computer because I didn't use it.你可能使用过我的游戏机。因为我不能使用它.you couldn’t have used my computer.你不可能使用过我的游戏机.3、Could h...
