你好,很高兴为你解答: 情态动词是一种本身有一定的词义,表示说话人的情绪,态度或语气的动词,但不能单独作谓语,只能和其他动词原形构成谓语。情态动词虽然数量不多,但用途广泛,主要有下列: can (could), may (might), must, need, ought to, dare (dared), shall (should), will (would) 。
情态动词+have done的意义如下: could have done本能够做某事而没做 must have done 肯定是做过某事 can/could not have done 不可能做过某事 may/might have done 可能已经做过某事 ought have done本应该做某事而没做