大学英语语法1.ppt

Revision 大学英语语法讲解 1.情态动词的完成时(表示对过去的说法) 2.虚拟语气的用法 3.Attributive Clause 4.倒装句 5.分词做状语 6.独 立主格 结 构 情态动词的完成时(表示对过去的说法) must +have +过去分词 （用于肯定句）一定已经……. The light is still on. They must have forgotten to turn it off when they left the room. 注:mustn’t have done × can’t (couldn’t) +have +过去分词 （用于否定或疑问句）不可能…….. He cannot have been to that town for I saw him just now. should/ought to +have+过去分词 本应该做(却没有做)……. As his best friend, you should/ought to have helped him. (but in fact, you didn’t.) shouldn’t /ought not to +have +过去分词 本不应该做(却做了)……. You shouldn’t have parked your car here, for it’s a public place. needn’t +have +过去分词 本不必做…… You needn’t have waited for me. I told you yesterday I would overwork. with with +A+ done With the homework finished, the boy went out. with +A+ doing With the old man leading the way, we finally find the house. with +A+ prep With the light on, all the students went out of the classroom. 虚拟语气的用法 概念：表示说话人的愿望、假设、猜测、或建议，而不表示客观存在的事实。虚拟语气通过谓语动词的特殊形式来表示 虚拟语气用于条件状语从句 (1) 与过去事实相反 If…had +done, …would (should, could, might) +have +done If you had taken my advice, you wouldn’t have failed in the exam. 与现在事实相反 If + did (be→were)，…would (should, could, might) + do If he had time, he would attend the meeting. If I were you, I should study English. 与将来事实相反 If + did (be—were) / were to / should+ do,…would (should, could, might) + do If you came tomorrow, we would have the meeting. If it were to rain tomorrow, the meeting would be put off. If 引导的虚拟条件句 虚拟语气用于宾语从句 在表示建议、要求、命令类的动词后面的宾语从句中用(should) + do。 如: advise, suggest, propose, request, require, insist, demand, order, command, desire We suggested that we (should) have a meeting. We insisted that the meeting (should) be cancelled. 注意：suggest 作“暗示，表明”解时，insist 作“坚决认为”解时不用虚拟语气，而用一般的时态。 Mike insisted that he had never stolen anything. Her sun-tanned face suggested that she was in excellent health. 虚拟语气用于主语从句 It is necessary (important, natural, strange, essential, etc.) that sb (should) +动词原形