情态动词+have_done结构一、“must+have+done” 表示对过去事情的肯定推测,译成“一定做过某事”,该结构只用于肯定句。 1. It must have rained last night, for the ground is wet. 昨晚一定下雨了,因为地面还是湿的。2. You must have been mad to speak to the servant. 你和仆人说话,一定是发疯了。二、 “cant+have+done” 表示对过去事情的否定推测,译成“不可能做过某事”。1. Mr. Smith cant have gone to Beijing, for I saw him in the library just now. 史密斯先生不可能去北京了,我刚才还在图书馆见过他。2. Mary cant have stolen your money. She has gone home. 玛丽不可能偷你的钱,她回家去了。三、 “can+have+done” 表示对过去行为的怀疑,