情态动词+have done must have done(仅肯定) 过去一定做过 might have done 可能做过 may have done (仅肯、否) 过去也许做过 may not have done 过去可能没有做过 can have done(肯、否、疑) 过去可能做过 can not have done 过去不可能做过 could have done 过去本来打算做但没做 could not have done 过去不可能做 should have done 过去本来应该做 need have done(否、疑) need not have done 过去本来不必做
